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Scuba Forum / General / March 2005A couple of Newbi ?s
My wife and I are heading down to the keys next week to get our open water cert. The operator recommended we use their gear for training, and buy our gear afterwards. Their concern was we would get outfitted with the wrong gear or sizes. (they don't sell a lot of gear, so thats not a conflict) Ultimately, I'm planning to purchase my gear from my LDS which is Bill Jacksons in St Pete FL. (They've got a great reputation in the community) They are not the cheapest solution, but they do have outstanding customer service, and will take the time to get us outfitted right. The guy I'm working with has been actively diving for 25+ years. I'm thinking I'd rather train in the gear I'm going to own, rather then rental gear. Any thoughts comments? One other - I'm debating between Sherwood and Scuba Pro for the reg. Is the scuba pro worth the extra $$? I know they have a great reputation, just not sure if its worth the permium over the others. TIA, JT > My wife and I are heading down to the keys next week to get our open water > cert. [quoted text clipped - 11 lines] > I'm thinking I'd rather train in the gear I'm going to own, rather then > rental gear. Any thoughts comments? Yes. Listen to the operator > One other - I'm debating between Sherwood and Scuba Pro for the reg. Is > the scuba pro worth the extra $$? I know they have a great reputation, > just not sure if its worth the permium over the others. Why don't you get some experience, try them both, and decide for yourself before spending the money? I'm also still newbish but .. When you are talking about something as critical (and expensive) as dive gear, shop for a store first, though it sounds like you have a decent LDS. The best service is far more important than the lowest price for most things .. The shop I like is about a 45 minute drive past the other two that are "Local", and the prices are all about the same. But the service is worth the time and effort. As far as gear goes I really think that the try before you buy rule works well, I recently purchased a wet suit but only after I had tried a few different rentals out ... and asked a few questions here. If I had bought right away, even based on advice from people whom I trusted, I would have ended up with something that was inappropriate for the diving I've been doing. The same thing would have happened with regs.. though I have not yet bought a reg I have learned that I really want one with an adjustable second stage, an option I would not have really cared about before I tried it out. Hey Andrew, You make me mighty curious. What is this thing you have with adjustable second stages? I always wondered, why would anybody ever induce a higher resistance in their main life support system? Please, enlighten me.  SignatureHES van Schoonhoven Life is a learning experience > I'm also still newbish but .. > When you are talking about something as critical (and expensive) as [quoted text clipped - 17 lines] > second stage, an option I would not have really cared about before I > tried it out. > Hey Andrew, > [quoted text clipped - 3 lines] > their main life support system? > Please, enlighten me. Same reason you induce a higher resistance on your exercise bike: it toughens you up. >>Hey Andrew, >> [quoted text clipped - 6 lines] > Same reason you induce a higher resistance on your exercise bike: it > toughens you up. ***** (five stars) > Hey Andrew, > [quoted text clipped - 3 lines] > their main life support system? > Please, enlighten me. The reasons are as different as the divers that use the regulators. Here are some of my reasons: 1. I started diving a long time ago. My first regulators breathed very hard by today's standards. Because it is what I am used to, I usually prefer to adjust my regulators to breathe a bit harder than most newer divers prefer. 2. Because I have adjusted my non-adjustable regulators to breathe a bit harder, I'm stuck with having that way for an entire dive. That's fine for the average dive, but not so fine when conditions make me want more air, faster and/or more easily, when I'm working against a current, for ecample. 3. A regulator that breathes very easily, often freeflows just as easily. Being able to adjust a regulator a bit during a dive, allows the diver to match it to changing conditions of the dive. Lee i don't know that i am explaining this correctly but.. However it happened I don't know but I seem to have a rather large lung capacity (my wife runs marathons and she breathes twice for every one of mine), I found that with the standard second stages I had to really concentrate on my breathing taking much shallower and quicker breaths than normal to keep myself from bouncing up and down and even then I wasted a lot of air. One of the dive masters noticed this and suggested that I turn up the resistance, it made an immediate difference, my breathing evened out, my hover became simple and most importantly I stopped being the first guy who had to ascend. I might be looking at them for the wrong reasons, I haven't done enough research yet but they on the top of the list at this point. > i don't know that i am explaining this correctly but.. > [quoted text clipped - 10 lines] > I might be looking at them for the wrong reasons, I haven't done enough > research yet but they on the top of the list at this point. Better breathing usually comes with experience, and more resistance makes you more aware of yer breathing. Deep breathing reduces CO2 retention, and you should strive for that. Most regs are very easy to adjust at home (or on the boat) if you know which end of a screwdriver goes in yer hand. External (knob/lever) adjustments are gimmicks that add complexity. > Most regs are very easy to adjust at home (or on the boat) if you know > which end of a screwdriver goes in yer hand. External (knob/lever) > adjustments are gimmicks that add complexity. True, but sometimes, not a lot of complexity. The replacement of a screw head with an external knob isn't usually a major issue. I got along with non adjustable regulators for a very long time. My G250 primary is the only one with externally adjustable cracking pressure I've ever owned. One or two of my others have some kind of venturi adjustment which can sometimes be handy in conditions that favor free flows. Lee > However it happened I don't know but I seem to have a rather large lung > capacity (my wife runs marathons and she breathes twice for every one > of mine) . . . I doubt that it's capacity. More likely the way you breathe, but the effect you describe is not uncommon. > I found that with the standard second stages I had to really > concentrate on my breathing taking much shallower and quicker breaths > than normal to keep myself from bouncing up and down and even then I > wasted a lot of air. Bad idea. > One of the dive masters noticed this and suggested that I turn up the > resistance, it made an immediate > difference, my breathing evened out, my hover became simple and most > importantly I stopped being the first guy > who had to ascend. Nice when things work out. As I mentioned in a previous message, I detune my regulators to get them to a workinglevel I am used to. With the adjustable models, I retain the option of easing access to gas if/when I wish. Lee For the newbi's In Europe a regulator must deliver 62,5 liters of air per minute at less then 2,5 KPa (=10" hydrostatic pressure), while the work of breathing may not exceed 3.0 Joules per liter. All at a depth of 50 meter. If it cannot comply it may not be sold. In the US Navy a regulator must deliver at least 62,5 liters of air per minute at less then 1.5 KPa (=6" hydrostatic pressure) while the work of breathing may not exceed 1.5 Joules per liter and all at a depth of 60 meter. If it cannot comply it is considered substandard and not to be used by the Navy. So ...? Obviously for the EC and the Navy the lowest possible resistance and work of breathing are among the most prominent factors determining quality and safety of a regulator. They seem to think that the diver should be able to breath effortlessly at all times. Not without reason: having to work harder for your breath then normally is very tiresome and gnaws away at your peace of mind. It won't kill anybody, but it may just shift the odds a little. Older, more experienced divers may have gotten used to the higher resistance of their older equipment and associate it with the fun they have underwater. They can live with it and as long as their regs give them what they want in a stressful situation, that's OK. But if you start now there is no reason to put up with less then the state of the art; with less then the lowest resistance the manufacturer could possibly set. That lightly tuned regs tend to free flow is a very, very lame excuse for any external adjustment. There really is no reason for any owner to bring this up. On the contrary, he should give the designer a good kick in the a.s, send him back to the drawing board to design a better front cap. SignatureHES van Schoonhoven Life is a learning experience >i don't know that i am explaining this correctly but.. > [quoted text clipped - 10 lines] > I might be looking at them for the wrong reasons, I haven't done enough > research yet but they on the top of the list at this point. > Hey Andrew, > [quoted text clipped - 3 lines] > their main life support system? > Please, enlighten me. Adjustable second stages are for folks that either (a) let a shop set up their reg and don't know how to adjust it themselves, or (b) buy a reg that won't stay in adjustment. > I'm also still newbish but .. > When you are talking about something as critical (and expensive) as [quoted text clipped - 17 lines] > second stage, an option I would not have really cared about before I > tried it out. I'm still diving the gear that I was "conned" into . . .lo those many years ago. Still love my regs . . .still find my BC works for me . . .oh yeah, I do have new fins . . . and I tried a bunch of different masks . . 10 years have gone by and when I wanted to find a mask that wasn't pink, but still fit me so well . . I found that the company was making the same mask under a different name . . .so my new mask is the same as the best mask that I have ever had . . it just isn't pink >Still love my regs . . .still find my BC works for me . . .oh yeah, I do >have new fins . . . [quoted text clipped - 3 lines] >new mask is the same as the best mask that I have ever had . . it just isn't >pink Real men don't use pink masks, or admit they love their legs. JF I bought all my gear two weeks before the class ended, Apeks regs, Zeagle BC mask fins etc. I knew I was going to but the stuff anyway, and while the equipment used in the class was good, It wasn't what I wanted to own. Since I was going to certify in 42 degree water at Bainbridge quarry in June wearing a 7 mill wet suit, I wanted to already be familiar with the functions of my equip. That was in 98, the only thing I have replaced is my snorkle, and I'm not sure why I did that. > Real men don't use pink masks, or admit they love their legs. I just use whatever I find on the bottom. If it's pink, that's fine, it matches my tutu. Which compliments my legs. >> Real men don't use pink masks, or admit they love their legs. > >I just use whatever I find on the bottom. If it's pink, that's >fine, it matches my tutu. Which compliments my legs. yeah, I know. I've dived with you, remember. I especially like the Mickey Mouse hands. JF >> Real men don't use pink masks, or admit they love their legs. > > I just use whatever I find on the bottom. That's how I got most of my snorkels. Lee > I'm thinking I'd rather train in the gear I'm going to own, rather then > rental gear. Any thoughts comments? This is the view that certain dive training agencies, namely SSI, drill into their instructors to drill into their students. The touted advantages are (1) you know exactly where everything is, (2) you know how the gear has been maintained, (3) the gear will fit you, and (4) you won't get another diver's cooties. However, (1) Gear configurations really don't differ that much among training agencies and most rental shops will give you a standard configuration. One exception to this rule is that some agencies, like PADI, have both primary and backup second stages coming from the right, while other agencies, like SSI, have the backup coming from the left. If the rental shop gives you a configuration opposite to the one you learned, it's a simple matter for them to reconfigure it. (2) Decent rental shops should keep their gear maintained to high standards, often to higher standards than some of us treat our own gear. It's always a good idea to check the hoses and connecting points to ensure that they're not too worn, and make sure that the mouthpiece is still in one piece. (3) Fit can be a concern, especially if you are extra extra large or odd shaped. Fit is a primary concern with wet (and dry) suits, a secondary concern with BCs, and no concern at all with regulators. If you're an off-the-rack kind of guy, don't worry. If you aren't, and may need thermal protection where you're going, a suit might be your first purchase. (4) Cooties are really hard to catch from other divers. Even if the rental shop failed to wash the gear before handing it to you, the ocean probably did the trick for them. If in doubt, bring your own mouthpiece and that will also solve the potential problem identified in (2) above. Also, if you have any qualms about using a wetsuit that someone else definitely peed in, follow my advice in (3) and buy your own wetsuit first. Even when you return from your trip, you may not want to purchase all your gear right away. Different shops have different motivations. Just because this shop owner seems like a really swell guy and is really experienced, you still might want to check around a bit, see what other divers like and don't like, and see what you like and don't like. There's still plenty of room for personal preference even with "standard" dive gear: jacket BC vs. back-inflate BC vs. backplate & wings. Air2 vs. octopus. All sorts of computers. All sorts of accessories that you really may or may not need. Your local shop owner, no matter how honest he might be, cannot possibly predict what your personal preference will be after you dive a bit simply because he's not you. So you risk either getting stuck with gear that you really don't need or want, or risk having to buy lots of new gear in the future and keeping the original stuff as backup or selling it on e-bay. It really comes down to your own comfort level in spending money. If you're filthy rich, go ahead and buy the gear now, buy some when you return, and buy some more in a year from now. The dive industry can always use more money. But if you're on a budget, delay the purchases until you're almost certain what you really want and there's no way to achieve that level of certainty without some experience. > One other - I'm debating between Sherwood and Scuba Pro for the reg. Is > the scuba pro worth the extra $$? I know they have a great reputation, > just not sure if its worth the permium over the others. Lifetime parts replacement, I believe, on the Scuba Pro. That alone might warrant the extra cost if Sherwood's warranty doesn't provide the same. >>snip of a VERY insightful well reasoned response. I am truly impressed!<< >>One other - I'm debating between Sherwood and Scuba Pro for the reg. Is >>the scuba pro worth the extra $$? I know they have a great reputation, >>just not sure if its worth the permium over the others. > > Lifetime parts replacement, I believe, on the Scuba Pro. That alone might > warrant the extra cost if Sherwood's warranty doesn't provide the same. I know that Sherwood used to give you the first 2 years free parts. And because their regs were so cheap to service, getting "free" parts for Scuba Pro didn't matter. To service my ancient Sherwood Maximus is like $35 including parts. > >>snip of a VERY insightful well reasoned response. I am truly impressed!<< > [quoted text clipped - 9 lines] > Scuba Pro didn't matter. > To service my ancient Sherwood Maximus is like $35 including parts. Yeah, baby . . . If no one thinks much of Sherwood regs, I'm still left asking myself why someone bothered to steal the Sherwood bumper off my first stage. Oh, yeah, and that little loss didn't make the slightest difference in how they breathe. >>I know that Sherwood used to give you the first 2 years free parts. And >>because their regs were so cheap to service, getting "free" parts for >>Scuba Pro didn't matter. >>To service my ancient Sherwood Maximus is like $35 including parts. > Yeah, baby . . . > If no one thinks much of Sherwood regs, I'm still left asking myself why > someone bothered to steal the Sherwood bumper off my first stage. > > Oh, yeah, and that little loss didn't make the slightest difference in how > they breathe. The dive shop where I first started talked me into buying all my gear. He said that if I were serious, I should become familiar with the stuff in the pool. Knowing that I had some spendable income, he made sure it passed in his direction. The Maximus was a good choice along with the SeaQuest Infinity BCD, Oneill 7mm wetsuit, US Divers Blades and Wenoka knives. I still have all that gear today and use everything except the BCD (which works fine. For pool work, I use the pool gear), I have gained a few OUNCES, so the wetsuit won't fit and I dive dry now. So, he made some money off me, and still today, I have all my gear. > The dive shop where I first started talked me into buying all my gear. He > said that if I were serious, I should become familiar with the stuff in > the pool. Knowing that I had some spendable income, he made sure it passed > in his direction. > The Maximus was a good choice . . . Don't know anything about it. > . . . along with the SeaQuest Infinity BCD . . . The BCD I used before I moved to a plate and wing. Mine was fine too, but I didn't buy it on recommendation. I bought it on features. In particular, I bought it because it had a right side, chest high D ring right where I wanted one. It was not my first BCD. I still have it. > US Divers Blades . . . Not my first choice. > and Wenoka knives . . . My larger knife is a Tusa. I like it better and got it for less than the Wenokas. My wife and I both have Tusas. She still uses hers. I now use two smaller knives of generic manufacture. You have to be careful with generic stuff, including knives. You can't always be sure of the quality. Mine are as good as any name brand. I would not be surprised if they are made by the same people. Lee >>The dive shop where I first started talked me into buying all my gear. He >>said that if I were serious, I should become familiar with the stuff in >>the pool. Knowing that I had some spendable income, he made sure it passed >>in his direction. >>. . . along with the SeaQuest Infinity BCD . . . > The BCD I used before I moved to a plate and wing. Mine was fine too, but I > didn't buy it on recommendation. I bought it on features. In particular, I > bought it because it had a right side, chest high D ring right where I > wanted one. It was not my first BCD. I still have it. I tried the BCD on in the shop. It felt comfortable and had a padded velor feel inside. Not the reason to buy a BCD for sure, but I didn't know any better. It turned out to work well for me. It provided enough lift for me and my steel 120, along with 20lbs of lead around my 7mm neoprene wetsuit self. >>US Divers Blades . . . > Not my first choice. I had no clue on blades to use. Because of my leg strenght, they were recommended. I have used them ever since. >>and Wenoka knives . . . > My larger knife is a Tusa. I like it better and got it for less than the > Wenokas. My wife and I both have Tusas. She still uses hers. I now use > two smaller knives of generic manufacture. You have to be careful with > generic stuff, including knives. You can't always be sure of the quality. > Mine are as good as any name brand. I would not be surprised if they are > made by the same people. I would love to by a no-name now. Looking for a nice titanium one. But to be still diving with my original knife says something about the quality of it. No rust pits at all. > Oh, yeah, and that little loss didn't make the slightest difference in how > they breathe. Of course not. Sherwoods breathe like sh.t no matter what you do to them. It's one of their best features. > > Oh, yeah, and that little loss didn't make the slightest difference > in how > > they breathe. > > Of course not. Sherwoods breathe like sh.t no matter what you do to > them. It's one of their best features. Since it's all I've ever used, I've never found it to be a problem for me. :^) >> > Oh, yeah, and that little loss didn't make the slightest difference >> in how [quoted text clipped - 5 lines] > Since it's all I've ever used, I've never found it to be a problem for me. > :^) Perhaps you are like me, you prefer what you are used to. I actually detune my none external adjustable regulators to "breathe like sh.t," compared to the all too easy breathing of recent models. I'm not particularly fond of regulators that help me breathe by providing gas an overpressure. Lee >>> > Oh, yeah, and that little loss didn't make the slightest difference >>> in how [quoted text clipped - 10 lines] >the all too easy breathing of recent models. I'm not particularly fond of >regulators that help me breathe by providing gas an overpressure. Wendy hates my Blizzard. She says she feels like it's forcing the air down her throat. Admittedly it's set up pretty sensitive. It freeflows easily but I like the breathing. It would be nice to be able to crank it back like I can my Apeks. JF > Since it's all I've ever used, I've never found it to be a problem for me. That's like a virgin saying she doesn't miss sex, babe. Signature"We're going to rush the hijackers." -Jeremy Glick, aboard United Airlines flight 93, September 11, 2001 > ? Since it's all I've ever used, I've never found it to be a problem for me. > That's like a virgin saying she doesn't miss sex, babe. How would a virgin know if she missed anything? You mean to say, "that would be like a person that had only ever had one partner thinking that's as good as it's gonna get". At least, that's what I've heard. Being a virgin and all, how could I really know? > You mean to say, "that would be like a person that had only ever had one > partner thinking that's as good as it's gonna get". Not only that, but you'd run around thinking 2x4's are eight inches wide. > At least, that's what I've heard. Being a virgin and all, how could I > really know? We'd tell you, honey. Signature"We're going to rush the hijackers." -Jeremy Glick, aboard United Airlines flight 93, September 11, 2001 >> Oh, yeah, and that little loss didn't make the slightest difference >in how >> they breathe. > >Of course not. Sherwoods breathe like sh.t no matter what you do to >them. It's one of their best features. I had long since forgotten that the Sherwoods weep a bit of air, and it's funny, because every time I see one doing it, I always think the owner has a malfunction, or pinhole leak in a hose somewhere, then I realize 'Oh, it's one of those Sherwoods'. Lee made a comment that he doesn't like overboosted second stages, and I, on the other hand prefer that 'push'. There is a reason, I am often standing upright, feet flat on the bottom, attaching hoist cables and so forth. Although there is only about 1 foot of differance in water depth between my mouth, and my lungs, in this upright position you will notice the slight squeeze on your mid-section, with a tiny bit of extra effort needed to breathe. I have only Oceanic Omega II's, which are a shower head like the Odin's. Most folks hate Omegas, but it is all I own. I do just a tiny bit of polishing on the plastic surface that the servo seats against, and these Omegas work so well for me that at times I nearly forget I am actually under water. It's like breathing naturally on the surface. My secondary air source is adjusted to require a bit more 'draw', don't want it to free flow!!! Guess it's all in what you like, and how you set it up. Even good gear can be set up to perform poorly. > Lee made a comment that he doesn't like overboosted second stages, and > I, on the other hand prefer that 'push'. There is a reason, I am often [quoted text clipped - 3 lines] > notice the slight squeeze on your mid-section, with a tiny bit of extra > effort needed to breathe. Which is one of two reasons why I like adjustable second stages. The other is for those occasions when I'm having to exert myself for one reason or another. It's nice to be able to dial in a bit easier access to gas. Lee " I had long since forgotten that the Sherwoods weep a bit of air, and it's funny, because every time I see one doing it, I always think the owner has a malfunction, or pinhole leak in a hose somewhere, then I realize 'Oh, it's one of those Sherwoods'." Don't get me wrong, I like Sherwoods. They just aren't the easiest breathing regs around. But they breath consistently, and reliabably. You can abuse the thing egregiously, and it will still deliver air. The Micras are crap, though. > This is the view that certain dive training agencies, namely SSI, > drill into their instructors to drill into their students. The touted > advantages are (1) you know exactly where everything is, (2) you know > how the gear has been maintained, (3) the gear will fit you, and (4) > you won't get another diver's cooties. > It really comes down to your own comfort level in spending money. If > you're filthy rich, go ahead and buy the gear now, buy some when you [quoted text clipped - 10 lines] > might warrant the extra cost if Sherwood's warranty doesn't provide > the same. Greg, Thanks for the lengthy reply. You brought up some great points! I have not been influenced on buying the gear ahead of time. Its more from: I live in Flordia; I know people who dive; and I know a people who dive and own boats! So, its really not a question of *if* I buy my own gear, but when. I've made up my mind to that and I'm ready to spend the cash. I'm not really worried about the maintenance or cooties. Its more like if your going deer hunting, do you want to borrow your buddies old gun, or use your own gun? You really don't know how your buddies gun behaves, or is sighted in. I'd rather have my own gun, one that I know, I've taken to the range and sighted in specifically for me, and one that I'm comfortable with. So I guess my desire is more from that comfort level you have with owning your own stuff, rather than borrowing others. I do appreciate the comments. I was ready to go lay out the cash this weekend, but now you've got me chewing it over. Thanks again, JT >I do appreciate the comments. I was ready to go lay out the cash this >weekend, but now you've got me chewing it over. > >Thanks again, Wait. You'll be glad you did. And if you're thinking of going on to do any tech type diving and are thinking that the starter regs you buy will serve as stage bottle regs later, forget the Sherwoods. They're great regs for the money, I have a Blizzard which has been bulletproof, and a darned good breather at the depths most of us do our diving., but Sherwoods have an airbleed outlet on them that allows a trickle of air to escape constantly from the first stage. Obviously this would be counter-productive on a stage bottle left on the bottom of a cave for hours or days. Empty stages suck. JF SNIP > And if you're thinking of going on to do any tech type diving and are > thinking that the starter regs you buy will serve as stage bottle regs [quoted text clipped - 7 lines] > > JF Dang, you made me think...I don't want to lose faith in my Sherwoods.... Please check my math, I've been known to omit the obvious.... 1. 15-30cc/min Sherwood air bleed rate by specs, I've always seen less 2. from Webster's Dictionary tables: 1 cubic inch=16.387 cubic centimeters, 1728 cubic inches=1 cubic foot 3. so, 30cc/16.387cc=1.8307194 ci/min 4. 1.8307194 ci/min divided by 1728=0.0010594 cf/min 5. 0.0010594 cf/min X 60 X 24 = 1.525536 cf/day Looks like about 1.5 cubic feet of air bleed over 24 hours. Fortunately, that's still within my personal safety margin, but, of course, I'm not employing DIR fail-safe techniques. 8^) When you said, "empty" stages suck, did you have some other figures in mind? Dave C > SNIP >> [quoted text clipped - 37 lines] > > Dave C It's a small amount but I still don't like to see bubbles coming from someones regulator. Adam > It's a small amount but I still don't like to see bubbles coming from someones > regulator. Some seem to wear their regs at strange places. Concealed carriage license? Matthias >>SNIP >> [quoted text clipped - 44 lines] > It's a small amount but I still don't like to see bubbles coming from someones > regulator. Then you don't have to look. There are tons of Sherwoods with little bubbles coming from the first stage. It is a part of their design. I have used a Sherwood Maximus for over 13 years with no problem. The reg is cheap to maintain and works. Now, if you are an Orek XL, this isn't the reg for you. I also have a Poseidon Odin (can't overbreath it at any depth if you tried) and Zeagle DS4/ZX which is another great breather (Apeks TX50/DS4). >Looks like about 1.5 cubic feet of air bleed over 24 hours. >Fortunately, that's still within my personal safety margin, but, of >course, I'm not employing DIR fail-safe techniques. 8^) > >When you said, "empty" stages suck, did you have some other figures in >mind? I remember a quote by someone from WKPP about stages left underwater for long periods of time. Perhaps someone here can expand on that. JF > I remember a quote by someone from WKPP about stages left underwater > for long periods of time. Perhaps someone here can expand on that. > > JF The dangerous thing for normal beings with the Sherwoods is another scenery. You can easily descend quickly enough to override the volume expanding in the bubbling channels, and thus create a relative vacuum, which will allow water being sucked in through the little rubber duckbeak check valve. Thsi water will make a mess in the little filter/orifice which controls the bleeding rate. This will prevent a proper depth compensation. Matthias >> I remember a quote by someone from WKPP about stages left underwater >> for long periods of time. Perhaps someone here can expand on that. [quoted text clipped - 9 lines] >controls the bleeding rate. >This will prevent a proper depth compensation. Never thought of that. Never heard it before either. Have you had experience with this? JF >>The dangerous thing for normal beings with the Sherwoods is another scenery. >> [quoted text clipped - 7 lines] > Never thought of that. Never heard it before either. Have you had > experience with this? I do not have Sherwoods. Two people died here in a never fully explained accident in an Bunker. This gave a starting point to analyse the regs behaviour under all possible conditions. Griends of mine made a thorough and documented test in a nearby quarry which is 50+m deep. Fast descents, having it as an unbreathed secondary, and such. Afterwards they dissected the reg to find the filter wet, and signs of corrosion (from before) in the reg where it shouldn't have been. Sherwood announced to sue them but did not. The website with the report is down, but I could perhaps manage to retrieve something. Matthias >I do not have Sherwoods. >Two people died here in a never fully explained accident in an Bunker. [quoted text clipped - 10 lines] >The website with the report is down, but I could perhaps manage to >retrieve something. I'd like to read whatever you can find. I'm not a hardcore Sherwood guy, but I tend to favour underdogs. 8) JF > >> I remember a quote by someone from WKPP about stages left underwater > >> for long periods of time. Perhaps someone here can expand on that. [quoted text clipped - 12 lines] > Never thought of that. Never heard it before either. Have you had > experience with this? I've descended as quickly as possible and never had that issue. OTOH, I've also found myself to breathing water with my air at depth. The consensus was a small wrinkle in the, um, what the heck is that thing called? > JF > > >> I remember a quote by someone from WKPP about stages left underwater > > >> for long periods of time. Perhaps someone here can expand on that. [quoted text clipped - 17 lines] > also found myself to breathing water with my air at depth. The consensus > was a small wrinkle in the, um, what the heck is that thing called? diaphram. > I've descended as quickly as possible and never had that issue. OTOH, I've > also found myself to breathing water with my air at depth. The consensus > was a small wrinkle in the, um, what the heck is that thing called? Lips? Matthias SNIP > The dangerous thing for normal beings with the Sherwoods is another scenery. > You can easily descend quickly enough to override the volume expanding > in the bubbling channels, and thus create a relative vacuum, which will > allow water being sucked in through the little rubber duckbeak check > valve. Thsi water will make a mess in the little filter/orifice which > controls the bleeding rate. > This will prevent a proper depth compensation. I think you've described a scenario that is only partially accurate, and not necessarily dangerous at recreational depths (< 130'). See what you think of my reasoning. You're right that a rapid descent (is there any other way on a scallop dive?) certainly will increase ambient pressure faster than the Sherwood piston's "flow control element" will allow air to pass into the dry ambient chamber to compensate (flow is about 15-30cc/min with a fully functioning new element). This pressure difference makes perfect sense, since the ambient chamber has a volume, I'd guess, of about 15cc or so, and I'm 80 feet down in less than a minute, trying to collect as many scallops as possible. Meanwhile, the ambient chamber pressure has to be raised from 1 ata to roughly 3.5 ata, at that depth, requiring roughly a minute or two to at the rate of the typical element. During that time, I've found I get all the air I need, with no noticeable change in effort, even though I'm probably breathing only a little less than an Oreck XL vacuum cleaner (I had to steal that great line, thank you, Tony P!). Seriously, I've always found the air delivery very good, even after quick descents. Also, with the resultant temporary pressure differential you correctly describe, the little rubber "duckbeak" check valve _should_ be squeezed down tight, right? If working properly, it's _not_ going to allow water to be "sucked in". The Sherwood "dry air bleed" design, with routine maintenance, usually does work as advertised. I might add, the Sherwood design was chosen and used by an Antarctic dive research team after significant comparison to other regulators. I think it's getting a bum rap in this thread. Check it out (unbelievable Antarctic uw pics in 200m vis): http://scilib.ucsd.edu/sio/nsf/index.html On the other hand, I can attest to one of your points from personal experience, that is, a little water _can_ get into the ambient chamber if it's an old Sherwood like one of mine, which occasionally _does_ leak a little because of corrosion where the "duckbeak" sits. Does this water "make a mess" in the bleed control element? Not in any dramatic or even noticeable fashion that I've seen. IMHO, the element will more likely clog over time in normal use with contaminants from the compressed air, I believe, when comparing one that has a bad seat under the "duckbeak" to one with a good seat. In my annual or even biannual servicing of these regulators (80 to 160 dives) there is usually no evidence of water infiltration or crap on the piston o-ring. Performance pressures usually are within normal specs prior to servicing. I also measure the output from the "dry air bleed" and it remains stable and within specs for years, indicating to me that the element is not getting clogged. Your other point about a lack of proper depth compensation when the flow control element is fully clogged is probably well taken; but a "dangerous" scenario? Not at recreational depths, I think. I've seen Sherwoods with fully clogged bleed control elements still breathe well. However, it makes sense that a regulator with a clogged flow control element might not _easily_ supply the gas needs of Johnny Oreck XL in panic mode at 150', but they still function pretty well. (there, I used that stolen line again- it's MINE now!) 8^) Regards. Dave C As is supposed to have happened in Kreidesee Hemmoor, a deep artificial lake in the western part of Germany: Two divers descend on al tech dive, stages and all. One of them uses Sherwood regs for his stage, but with the valve turned off and the first stage not presursed, there is no spill and it floods. When they ascend, fully dependent on their stages, this one diver ends up dead. Sorry, I wasn't there and cannot comment any further on all the things they did and did not do 'right', but the flooding of the first stage must have been the determinant cause of the accident. I myself would be very suspicious over the bleed system, mostly because I would expect it to clog, but this is the only real mishap with the system I ever heared off. SignatureHES van Schoonhoven Life is a learning experience > SNIP >> The dangerous thing for normal beings with the Sherwoods is another [quoted text clipped - 76 lines] > > Dave C > As is supposed to have happened in Kreidesee Hemmoor, a deep artificial lake > in the western part of Germany: This was in a concrete bunker in Giessen, Hes. Matthias > As is supposed to have happened in Kreidesee Hemmoor, a deep artificial lake > in the western part of Germany: [quoted text clipped - 8 lines] > did and did not do 'right', but the flooding of the first stage must have > been the determinant cause of the accident. Not enough info here for conclusions, but just enough to spawn an Urban Legend, unfortunately. I'm trying to think how a flooded ambient chamber (the normal circumstance for many other designs) would somehow cause a major failure and fatality as rumored. I can't picture what else might flood. More info would be helpful. > I myself would be very suspicious over the bleed system, mostly because I > would expect it to clog, but this is the only real mishap with the system I > ever heared off. I'm not sure I'm capable of figuring out the degree of effect of a clogged bleed system (and subsequent lack of depth compensation) on the effort of breathing and volume of air delivered at various depths. Might be interesting, though. >From what I've experienced with Sherwoods in circumstances approximating that condition, any effect was not noticeable at 80 feet. This summer, I might set up a Sherwood to create those conditions and do some testing at recreational depths. On a pony bottle, of course....no sense being overconfident. 8^) Dave C > You're right that a rapid descent (is there any other way on a scallop > dive?) certainly will increase ambient pressure faster than the > Sherwood piston's "flow control element" will allow air to pass into [quoted text clipped - 3 lines] > or so, and I'm 80 feet down in less than a minute, trying to collect as > many scallops as possible. OK. > Meanwhile, the ambient chamber pressure has to be raised from 1 ata to > roughly 3.5 ata, at that depth, requiring roughly a minute or two to at [quoted text clipped - 3 lines] > (I had to steal that great line, thank you, Tony P!). Seriously, I've > always found the air delivery very good, even after quick descents. OK. > Also, with the resultant temporary pressure differential you correctly > describe, the little rubber "duckbeak" check valve _should_ be squeezed > down tight, right? If working properly, it's _not_ going to allow water > to be "sucked in". It should. However, if you look at other checkvalve designs, you'll find many which are much more precise than Sherwood' is here. So I'd better count on some water ingress sooner or later. > The Sherwood "dry air bleed" design, with routine maintenance, usually > does work as advertised. I might add, the Sherwood design was chosen > and used by an Antarctic dive research team after significant > comparison to other regulators. I think it's getting a bum rap in this > thread. Once in the water, the Antartic is no more that special. A friend of mine has been there for research, for several month on several occasions. They used their standard scientific divers gear, Poseidon Cyklons. No problems. > On the other hand, I can attest to one of your points from personal > experience, that is, a little water _can_ get into the ambient chamber [quoted text clipped - 5 lines] > compressed air, I believe, when comparing one that has a bad seat under > the "duckbeak" to one with a good seat. That as well... May be a contending reason why the Hamburg Greenpeace diving team disliked them, saying they did not deliver well beyond 30m. Seems the IP compensation was badly affected. > In my annual or even biannual servicing of these regulators (80 to 160 > dives) there is usually no evidence of water infiltration or crap on > the piston o-ring. Performance pressures usually are within normal > specs prior to servicing. I also measure the output from the "dry air > bleed" and it remains stable and within specs for years, indicating to > me that the element is not getting clogged. It seems to be rather specific to the individual. I alos know guys who are completely satisfied with their Sherwoods. > Your other point about a lack of proper depth compensation when the > flow control element is fully clogged is probably well taken; but a > "dangerous" scenario? Not at recreational depths, I think. Well, I tend to call any depth I'd like to dive a rec depth. And any reg I dive should meet this requirement. Remember that even i a well functioning reg tha ratio between ambient pressure and intermediate pressure drops with depth. In a non compensated reg with, say, 9 bar intermediate pressure, your ratio drops from 9/1 at tha surface to 9/5 at 40m, whereas it should drop from 9/1 to 14/5, which would mean a 55 percent better performance with the bleeding system fully working. Matthias SNIP > > Your other point about a lack of proper depth compensation when the > > flow control element is fully clogged is probably well taken; but a > > "dangerous" scenario? Not at recreational depths, I think. > > Well, I tend to call any depth I'd like to dive a rec depth. And any reg > I dive should meet this requirement. Good point. I just didn't want to make too specific a depth recommendation. > Remember that even i a well functioning reg tha ratio between ambient > pressure and intermediate pressure drops with depth. > In a non compensated reg with, say, 9 bar intermediate pressure, your > ratio drops from 9/1 at tha surface to 9/5 at 40m, whereas it should > drop from 9/1 to 14/5, which would mean a 55 percent better performance > with the bleeding system fully working. > > Matthias This is helpful. I've been trying to figure out the effect of loss of depth compensation and was reaching similar conclusions, but was too cautious to state it publicly. It explains why the effect is not noticeable at normal breathing rates at the 80' depths I mentioned. In a non-compensated regulator, depth will also affect cracking pressure in a linear fashion, right? I was trying to figure out what depth would make cracking pressure a significant issue. I was thinking of measuring subjective inhalation effort negative pressures....yes, I'm getting lazy.... Dave C > In a non-compensated regulator, depth will also affect cracking > pressure in a linear fashion, right? I'd suggest it is more of a design question. Upstream, downstream, balanced or not. In a balanced design, it is the force of your intercostal muscles which create the vacuum which opens the valve. Take a Draeger age old Secor 200 secons stage as an example: The valve mechanism opens against IP, its crosssection is a T, where the bottom bar is actuated by the diaphragm. It then tilts the plate, which is held clamped to the seat by a cylindrical spring. So you'd think, the more pressure acts in parallel with the spring, the higher the cracking pressure. But that is not what you feel. In fact, once a tiny bit opened, the valve plate is dynamically balanced, and I have used this reg with IPs from 4,5 bars to 10. >I was trying to figure out what depth would make cracking pressure a significant issue. I was thinking > of measuring subjective inhalation effort negative pressures No problem. make an in between stud between the mouthpiece, prolonging the reg's one. With a T leading to a vac-meter, or U-shaped transparent scaled tubing, or motorcycle carburettor sync-bench. Compare. The IP is necessary to overcome all the internal resistances in a 1st-2nd stage assembly, that is bends, sharp edges, filter, cornes, adjacent hose-joints, hose length, gas density, ambient pressure. The better designed a reg is, the lower an IP it would need to achieve that. Matthias > I do appreciate the comments. I was ready to go lay out the cash this > weekend, but now you've got me chewing it over. It's worth thinking about a bit. If you look closely, you'll find that Greg recognizes the points that have led you to decide to buy your own equipment. Greg, like pretty much all of us here, bought his own equipment for at least some of the same reasons. The question is not if, but what and when to buy. The wise answer is to buy when only when you know what. Many of us, including me, did not heed our own advice. We've got rooms full of stuff that proved not to be the right product for us. I started out with US Divers many years ago. I was always happy with the performance of their products. I changed over to Scuba Pro a few years ago. My Scuba Pro regulator does breathe a bit easier than my USD ones do, but both are acceptable. If I had it to do over, I'd might make the change again, but I also might chose still another brand, Apex/Apecs (sp?). I'd have to try them first. The point Greg and several others are trying to make is that the more products you try a while before you buy, the more likely you are to get something you'll be happy with for longer. Lee >(snip)> Lifetime parts replacement, I believe, on the Scuba Pro. That alone might > warrant the extra cost if Sherwood's warranty doesn't provide the same. 10 years of Sherwood Maximus . . . as I recall, there's never been a need to have a part replaced. Sure people make fun of my picture on the tour agency website. Regardless, I'm reasonably confident it's the pink mask and not the Sherwood regs . . .that really keeps them rollin' in the aisles. >>(snip)> Lifetime parts replacement, I believe, on the Scuba Pro. That >alone might [quoted text clipped - 6 lines] >I'm reasonably confident it's the pink mask and not the Sherwood regs . . >.that really keeps them rollin' in the aisles. Compared to SP, Sherwood has hardly any parts to be replaced. I suppose they had to stick in a few extra bits for the adjuster but otherwise it's simplicity. And my Blizzard breathes every bit as nicely as any of my Apeks (spelling note to Lee) at normal rec diving depths. I loaned my Blizzard to a DM in Mexico this year and he raved about how nicely it worked. Of course he was comparing it to the rentals they use in their shop. A cave diver friend of mine in Mexico got rid of all his Sherwood rental gear once he stopped working in OW. He said the only reason was the airbleed. He liked how easy they were to maintain and the dependability, but he switched to SP and sounds like he might be checking out Apeks now. JF > Compared to SP, Sherwood has hardly any parts to be replaced. I > suppose they had to stick in a few extra bits for the adjuster but > otherwise it's simplicity. And my Blizzard breathes every bit as > nicely as any of my Apeks (spelling note to Lee) at normal rec diving > depths. Thanks for the spelling note. I wish I could promise to remember it.+ > I loaned my Blizzard to a DM in Mexico this year and he raved about > how nicely it worked. Of course he was comparing it to the rentals > they use in their shop. When my high pressure hose went out in Coz, I swapped my detuned Micra with one of the DMs in Coz. He gave it back the next dive. He could not stand it. Apeks is the only regulator company I know of that I've heard will sell rebuild kits to the public. Lee > 10 years of Sherwood Maximus . . . as I recall, there's never been a need to > have a part replaced. I have had the Maximus a few years longer and HAVE had to have a part replaced. You know that little screw and lockwasher that holds the resistance knob in place? Well, it had finally worked it's way loose. Now, for about a buck, I have to replace it. A great reg. It's been on dives with me to the Andrea Doria and other "deep" stuff. Not my primary now, but was for a long long time. > > 10 years of Sherwood Maximus . . . as I recall, there's never been a need to > > have a part replaced. [quoted text clipped - 5 lines] > dives with me to the Andrea Doria and other "deep" stuff. Not my primary > now, but was for a long long time. Geez, now that you mention it, I've had to have a screw replaced on mine too. The one fault I've been able to find with my reg, is that the swivel loosens the screw on that side of the cover. >> 10 years of Sherwood Maximus . . . as I recall, there's never been a need to >> have a part replaced. [quoted text clipped - 5 lines] >dives with me to the Andrea Doria and other "deep" stuff. Not my primary >now, but was for a long long time. As a point of interest, was the breathing noticeably tougher at 200+ ft? I've been assured that's where Sherwoods lose their appeal, but not having gone down there I wouldn't know from experience. JF >>I have had the Maximus a few years longer and HAVE had to have a part >>replaced. You know that little screw and lockwasher that holds the [quoted text clipped - 6 lines] > ft? I've been assured that's where Sherwoods lose their appeal, but > not having gone down there I wouldn't know from experience. It was no tougher than 120'. If you breathe like an Orek XL vacuum cleaner, this is not the reg for you. My Poseidon Odin is almost impossible to overbreathe and seemed to deliver "more" air with less resistance than the Sherwood. The Sherwood has given me many many years of trouble free service. Would I consider it a "tech" reg? No. But an excellent recreational reg, most definatly. >>(snip)> Lifetime parts replacement, I believe, on the Scuba Pro. That > alone might [quoted text clipped - 6 lines] > I'm reasonably confident it's the pink mask and not the Sherwood regs . . > .that really keeps them rollin' in the aisles. Maybe it's not the scuba gear that gets em rollin. Adam >>I'm thinking I'd rather train in the gear I'm going to own, rather then >>rental gear. > (1) Gear configurations really don't differ that much among training > agencies and most rental shops will give you a standard configuration. . If the rental shop gives you a > configuration opposite to the one you learned, it's a simple matter for them > to reconfigure it. I can see some potential merit to training in the gear you're going to dive in, but what happens if you ever decide to change any of that gear? Sooner or later you're going to have to get used to different gear, but that shouldn't be a problem for anybody who already learned how to dive. Note that "already learned how to dive" may be different than "already got certified". To a large extent there won't be anything dramatically different about new gear, anyway. If anybody is ever concerned enough about getting used to new gear they can always take PADI's "Getting used to your new gear" course. SignatureSteve The above can be construed as personal opinion in the absence of a reasonable belief that it was intended as a statement of fact. If you want a reply to reach me, remove the SPAMTRAP from the address. >>>I'm thinking I'd rather train in the gear I'm going to own, rather then >>>rental gear. [quoted text clipped - 12 lines] >be different than "already got certified". To a large extent there won't be anything >dramatically different about new gear, anyway. I trained using Scubapro, never used any since. Nothing against it, just haven't. I did rent for a while before buying. I'm now on my second regulator in almost 20 years of diving. Second BC, too. You should buy gear as if you were going to keep it for a while. And buy it as if your life depended on it. >If anybody is ever concerned enough about getting used to new gear they can always >take PADI's "Getting used to your new gear" course. Unfortunately, all I can offer is a Distinctive Speciality patch. It's not a formal specialty. Signaturedillon "When the French are against it, you know we can't be far wrong." - Adm. Bobbie Ray Inman > My wife and I are heading down to the keys next week to get our open water > cert. [quoted text clipped - 19 lines] > > JT I'd wait - it is a major investment, but if you trust the guy you're buying from...... Using different gear lets you make the decision - not the guy selling the equipment > My wife and I are heading down to the keys next week to get our open water > cert. > > The operator recommended we use their gear for training, and buy our gear > afterwards. Their concern was we would get outfitted with the wrong gear > or sizes. (they don't sell a lot of gear, so thats not a conflict) Other than your mask, fins, and snorkel, do not buy any gear from anyone until you have much more experience. Rent, borrow, use demo gear, but don't buy. If you must buy, buy it from one of the many divers that bought as soon as they were certified (or before) and now realize that they have gear that is not appropriate for their kind of diving. Trust me! If you get gear before you get some experience, you'll regret it. m Thanks to all for the feedback. I've taken the advice, and going to hold off and shop around. Looking forward to training in the keys next weekend! Thanks again, JT >Thanks to all for the feedback. I've taken the advice, and going to hold >off and shop around. > >Looking forward to training in the keys next weekend! Don't forget to have fun. 8) JF |
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