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Scuba Forum / UK Scuba / February 2006"Plotting" a wreck on a map?
Hello, all. I am doing some reseach for a book into the histories of several WWI vessels that were sunk in the waters off of England and Ireland. As far as I can tell from my research so far, these wrecks have not been located or dived on yet. However, I have rough information about where they went down, i.e., a ship that went down at 38 miles W by S of a particular coastal location. If I wanted to plot that on a map, is that even enough information to give a general idea of where the wreck might be? If so, would you measure 38 miles west of that point, and then 38 miles south of the point you measured? As is probably painfully evident, I have no experience in this matter and any guidance would be greatly appreciated. At the moment a ballpark estimate of where the wreck might be and how deep the water is in the area is what I'm hoping to get. Many thanks, -ph0ebus > I am doing some reseach for a book into the histories of several WWI > vessels that were sunk in the waters off of England and Ireland. As [quoted text clipped - 4 lines] > that even enough information to give a general idea of where the wreck > might be? It depends on how general an idea you consider valuable and how accurate the measurement is. Unless it was a relatively recent wreck, both the bearing and the distance are likely to be approximations. It would give you an idea of the general area, but it probably would not let you find the wreck without searching a very wide area. > If so, would you measure 38 miles west of that point, and then 38 miles > south of the point you measured? No, I would measure 38 miles SW, assuming that's what W by S means. Understand, however, that every degree of error in the direction adds up to quite a variation in location over a run of 38 miles. It normally takes two sightings to get a reasonably close position. > As is probably painfully evident, I have no experience in this matter and > any guidance > would be greatly appreciated. At the moment a ballpark estimate of where > the wreck might be and how deep the > water is in the area is what I'm hoping to get. That you can probably do, but it will take a combination of tools. Start with Google Earth, http://earth.google.com/ . Don't pay for the upgrade. It won't do you any good at this point. Select measure, click on the landmark and move the cursor 38 miles to the SW. That's as close as you're likely to get. Put a waypoint mark on the spot and record the latitude and longitude. Then get a chart of the area, find the same latitude and longitude and get the depth from the chart. Electronic charts, like the Garmin Blue Chart software I use with my GPS's. While you're doing all of this, take a look at how much even a few degrees of angle change the area where the wreck most likely is. Good luck. Lee >> I am doing some reseach for a book into the histories of several WWI >> vessels that were sunk in the waters off of England and Ireland. As [quoted text clipped - 18 lines] >quite a variation in location over a run of 38 miles. It normally takes two >sightings to get a reasonably close position. I can just attest to the difficulty of finding a wreck after having re-localised "Drammen" from older dive descriptions and the original reports from the sinking in 1914. Even if we had the area down to a 3x6 cables (=1/10th nautical mile) it took close to 20 dives to locate it. >> As is probably painfully evident, I have no experience in this matter and >> any guidance [quoted text clipped - 12 lines] >this, take a look at how much even a few degrees of angle change the area >where the wreck most likely is. You also need to be aware that the datum of the charts you use and what they used may differ significantly. Their position may also have been off, as they most likely stated their calculated position. This can be off by a lot. If they had access to observing sun or stars it is pretty likely that the latitude is correct within a few cables; it takes a bit of calmer weather to have the longitude correct. Meterological observations from the time of the sinking is therefore valuable. You may find it helpful to retrace their likely navigational steps using original charts and tables from the correct time. It also helps to take a few trips bringing charts around fishermen. They usually know where the wrecks are. Underwater terrain within 60 nautical miles from land is usually fairly well known by sailors and fishermen that have been watching the sonar for weeks on end. So, it may be a helpful approach to start in the other direction and look at the "bumps in the underwater terrain". I have myself located a few "suspicious bumps in the underwater terrain" on the sonar while sailing. They are mostly in the 50-70 m area, and I am considering building myself a cheap drop-down camera for a little series of inspections. -- mrr > they went down, i.e., a ship that went down at 38 miles W by S of a > particular coastal location. If I wanted to plot that on a map, is [quoted text clipped - 5 lines] > where the wreck might be and how deep the water is in the area is what > I'm hoping to get. You need the Admiralty chart for the area, not a map. You'll obtain this from your local Admiralty Chart stockist, or you can probably get one by Mail Order from Small Craft Deliveries in Woodbridge who are our local stockists. 38 miles W by S probably means a distance of 38 nautical miles on a bearing of 225 degrees from your coastal location. That will give you a rough position for the reported site and from that you'll get information on depth, bottom type and known wrecks and obstructions in the area. It's also possible to buy more information from the Admiralty for a particular area of sea that will give you more information on the wrecks and known obstructions. It's surprising just how many 'unknowns' are known to the professionals (having a Rumsfeld moment there!) And there are other sources such as Richard Larn's shipwrecks of the British Isles. Local skippers and notable wreck researchers such as Leigh Bishop and Innes McCartney might have more information , and then there is the National Maritime Museum. One thing to bear in mind that the position you have is likely to be very approximate. It may be the position that the ship was damaged, rather than its sinking position. For example the Princess Juliana lies at the end of Felixstow Pier, but all the sinking records point to the place where it was torpedoed, about 300 miles away in the channel. Pete  Signature------------------------------------------------------------------------ Pete Young pete@antipope.dot.org Remove dot. to reply "Just another crouton, floating on the bouillabaisse of life" Hi again, Pete Young did state: >It's also possible to buy more information from the Admiralty for a >particular area of sea that will give you more information on the >wrecks and known obstructions. It's surprising just how many >'unknowns' are known to the professionals (having a Rumsfeld moment >there!) Actually, this is what I am hoping is the case. I am actually looking to locate two specific wrecks: The Anchor Line's TSS California, torpedoed Feb 8, 1917 by U-85 38 miles W by S of Fastnet Island, and the wreck of U-85, who was sunk by the British Q-Ship HMS Privet on March 12, 1917, located at 5002N 0413W (another source says 49.52N 03.20W ) in the English Channel. Either of these wrecks sound familiar? Pete continued: >One thing to bear in mind that the position you have is likely to be >very approximate. It may be the position that the ship was damaged, >rather than its sinking position. For example the Princess Juliana >lies at the end of Felixstow Pier, but all the sinking records point >to the place where it was torpedoed, about 300 miles away in the >channel. I would suspect this is true in this case. She (the California) was under full steam when she was sunk, and lost little headway from the time she was struck by the torpedo until she went down nine minutes later. Naturally, if you know that either wreck has been located, that would come as great news to me. If not, then your leads will be very helpful indeed in giving me a start in the right direction. Many thanks, -ph0ebus > Actually, this is what I am hoping is the case. I am actually looking > to locate two specific wrecks: The Anchor Line's TSS California, [quoted text clipped - 3 lines] > 03.20W ) in the English Channel. Either of these wrecks sound > familiar? I was talking bollocks earlier - West by South is roughly 260 degrees. I don't know whether either of these wrecks is confirmed at these positions. The first one is roughly on the way to the Carpathia, maybe Richie Stevenson of Deep Blue would know about it! For the U-boat, start with Innes McCartney. From what Tony says this one is right in the area where I'd expect people to be diving. You can probably reach him through www.periscopepublishing.com . Pete Signature------------------------------------------------------------------------ Pete Young pete@antipope.dot.org Remove dot. to reply "Just another crouton, floating on the bouillabaisse of life" > I was talking bollocks earlier - West by South is roughly 260 degrees. West by South is one of the 32 points of the compass and lies between west and west-southwest (i.e. 258.75 degrees). "By" is an old-fashioned usage meaning "tending towards". Here are the rest of the points: 000.00 N 011.25 N by E 022.50 NNE 033.75 NE by N 045.00 NE 056.25 NE by E 067.50 ENE 078.75 E by N 090.00 E 101.25 E by S 112.50 ESE 123.75 SE by E 135.00 SE 146.25 SE by S 157.50 SSE 168.75 S by E 180.00 S 191.25 S by W 202.50 SSW 213.75 SW by S 225.00 SW 236.25 SW by W 247.50 WSW 258.75 W by S 270.00 W 281.25 W by N 292.50 WNW 303.75 NW by W 315.00 NW 326.25 NW by N 337.50 NNW 348.75 N by W Phil S > Actually, this is what I am hoping is the case. I am actually looking > to locate two specific wrecks: The Anchor Line's TSS California, [quoted text clipped - 3 lines] > 03.20W ) in the English Channel. Either of these wrecks sound > familiar? > Many thanks, > > -ph0ebus any reason why you are looking for these two. did you know anyone on them ? David > any reason why you are looking for these two. did you know anyone on them ? Actually, yes; my great granmother and her children came to America on the California from Scotland in 1908. I started on this "quest" just by casually wondering whatever happened to the ship, then read the dramatic story of it's sinking and was hooked. That naturally led to the question of who sank her, and what happened to them, etc. and what started with one simple question has grown into a book in the making. -ph0ebus Hi again, Pete Young did state: >It's also possible to buy more information from the Admiralty for a >particular area of sea that will give you more information on the >wrecks and known obstructions. It's surprising just how many >'unknowns' are known to the professionals (having a Rumsfeld moment >there!) Actually, this is what I am hoping is the case. I am actually looking to locate two specific wrecks: The Anchor Line's TSS California, torpedoed Feb 8, 1917 by U-85 38 miles W by S of Fastnet Island, and the wreck of U-85, who was sunk by the British Q-Ship HMS Privet on March 12, 1917, located at 5002N 0413W (another source says 49.52N 03.20W ) in the English Channel. Either of these wrecks sound familiar? Pete continued: >One thing to bear in mind that the position you have is likely to be >very approximate. It may be the position that the ship was damaged, >rather than its sinking position. For example the Princess Juliana >lies at the end of Felixstow Pier, but all the sinking records point >to the place where it was torpedoed, about 300 miles away in the >channel. I would suspect this is true in this case. She (the California) was under full steam when she was sunk, and lost little headway from the time she was struck by the torpedo until she went down nine minutes later. Naturally, if you know that either wreck has been located, that would come as great news to me. If not, then your leads will be very helpful indeed in giving me a start in the right direction. Many thanks, -ph0ebus > Actually, this is what I am hoping is the case. I am actually looking > to locate two specific wrecks: The Anchor Line's TSS California, > torpedoed Feb 8, 1917 by U-85 38 miles W by S of Fastnet Island This is heading out into the Atlantic will find you in 150 - 160M of water, beyond the reach of most of us. > the wreck of U-85, who was sunk by the British Q-Ship HMS Privet on > March 12, 1917, located at 5002N 0413W (another source says 49.52N > 03.20W ) in the English Channel. The first is about 8 miles south of the Eddystone. The second is mid way between Start Point and the Channel Islands, not to far from a mid channel shipping separation zone (a tricky place to dive). The two are about 35 miles apart and both are going to be 70ish metres deep. Tony Hi Guys Have you tried http://users.pandora.be/tree/wreck/wreck-database/detail_query.html?filter=1605 This gives a location for U85, not much else though, and nothing on the California Good Luck Andy > Hi again, > [quoted text clipped - 34 lines] > > -ph0ebus Wow, this is a great resource. It appears that this DB hasn't got the California's area covered at present. I'm following up with the people who run the site to see if that is planned or if they know of others who plan on mapping that area and putting it up on the net. I will also continue doing archival research at the New York Public Library to see what further information I can gather about where the wreck of the California might be. I've got a few things that are making things difficult, mainly that I'm in the US, not the UK, and I'm squarely outside of my element in that I am not a diver. At some point I would hope to learn to dive and travel to Ireland to pursue this but there's quite a bit of learning I have to do between now and then I'm a bit concerned that what it will take to find this wreck will parallel the search for and exploration of the Titanic. The problem, of course, is that the California is an obscure wreck, it's not a treasure ship or even slightly famous. If this wreck is in really deep water, who has the time and resources to devote to finding it? Sadly, not me (unless the lottery comes though...I'm not holding my breath). That won't keep me from trying, though. If anyone is interested, I'll post updates in this forum as more information comes to light. All the best, -ph0ebus > Wow, this is a great resource. Indeed, andit appears to be copying other people's carefully researched and published info: http://users.pandora.be/tree/db/story/strathclyde.html is a ripoff of copyright from my website: http://www.peardrop.co.uk/dover_wrecks.htm - Keith Sorry Keith, Don't shoot the messenger, I found the site about a year ago, just thought it might be useful. I have no connection with the site, just found it useful in the past. Andy >> Wow, this is a great resource. > [quoted text clipped - 8 lines] > > - Keith > Sorry Keith, > [quoted text clipped - 3 lines] > > Andy It is a good site, but it's always nice to be asked before someone uses your own material. I'll be happy if they give me a credit for what I wrote. - Keith >> they went down, i.e., a ship that went down at 38 miles W by S of a >> particular coastal location. If I wanted to plot that on a map, is [quoted text clipped - 13 lines] > 38 miles W by S probably means a distance of 38 nautical miles on > a bearing of 225 degrees from your coastal location. yes but unless you know that was an accurate heading ... what that gives you is a arc of interest, could actually be anything from 180 digress to 270 degrees, if you assume they were good at their heading that would still reduce the arc to be between SSW to WSW 202.5 degrees to 247.5 degrees. This is a still HUGE margin for error (or search) Think of it this way ... as a circle ... the centre of which is your point of origin on land. Use a compass to draw a circle with radius of 38 miles (obviously do this to a suitable scale on paper or the chart. Draw a line out from centre at 202.5 degrees until it reaches circumference (point A) ...draw another at 247.5 degrees.(point B) Now draw a line joining A and B (subtending the arc to give the flashy term) That line is the distance along which your search would have to be. That is not allowing for drift before sinking, bottom shift etc. A rough guide is that it is a shade under 30 miles ! If you assume (unfortunately probably wrongly without proof) that they were accurate you could reduce this to a 22.5 degree cone of interest, but it would still give search line between the 2 tangents of just under 15 miles. This is the problem with only having one point of reference ... the single coastal point, if you had a second point from which you had a heading you could dramatically reduce the search area. Rick "ph0ebus" <ph0ebus@optonline.net> wrote in news:1138831058.686233.233720 @o13g2000cwo.googlegroups.com: > Hello, all. > [quoted text clipped - 3 lines] > might be? If so, would you measure 38 miles west of that point, and > then 38 miles south of the point you measured? A Try this link for an explanation of the compass direction W by S. http://www.thefreedictionary.com/west+by+south hope this helps |
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