The value of snorkels is inversely proportional to their price. The very
best snorkels are the very cheapest, the worst snorkels are the most
expensive. Buy the cheapest you can find online.

Fins for occasional snorkeling can also be bought cheap, especially at
the sports warehouses or online. Cheap fins usually need a pair of heavy
socks to keep yer feet from chafing. Or rent.

The mask, however, needs to be bought with care, NOT online. Go to a
retailer that has a wide variety of masks and try them for fit (without
using the strap, you should be able to hold the mask to your face with
just the very slightest negative pressure through yer nose, with no air
leaks around the skirt). When (if) you find a mask that fits, buy it. If
it's a $30 mask, yer lucky. If it's a $70 mask, yer not so lucky. A mask
that fits well will give you many years of enjoyment. A mask that fits
poorly will be living hell after five minutes.

Enjoy yer trip.

I suggest you get your own snorkel and mask. Other people have covered the
mask thing pretty well.  The snorkels you get with rental gear will almost
certainly be cheap and usually don't even have a bailer to drain water out.
You have to deal with any water that comes in by blowing it out, like a
surfacing dolphin.  Not my idea of a good time, especially for beginners.
Snorkeling is so much more pleasant when you don't have to deal with water
in your snorkel.

I'm very fond of my OceanMaster dry snorkel. You can see the model on the
web at http://www.oceanmaster.com/SnorkelsFeatures.htm#Dry, and you can buy
it at many local dive shops.  When they say "dry" they mean it.  Mine is dry
when I free dive, and when waves crash over my head, and when I tilt your
head too far looking it stuff around me.  The only time I ever had a water
problem was once when I slooooooowly ducked my chin to my chest to watch the
remora trying to attach itself to my stomach.  But realistically, that
probably won't be a problem for you :-)  For a quick duck like you get if
you turn to look at something in a hurry or take a quick peek behind you, it
stays dry. I saw it in a store recently for $39, which isn't so much when
you consider how much more pleasant your experience is.

I have no connection to the company, except that I love their product.  I've
had mine for many years.  My husband used to refuse to snorkel with me until
I got him a dry snorkel. Now, he'll go along with me. I don't think he likes
it yet, but at least it's no longer unpleasant.

The model I have has a ball joint near the mouthpiece, so you can adjust its
position to a comfortable angle for your particular way of looking around. I
saw a model in stores a couple of years ago that had an accordion pleated
tube but no ball joint. You can't adjust the position of that model, so I
wouldn't recommend it.  I don't know if they make that model  anymore. Their
web site shows a model that has both the pleated tube and the ball joint,
which is probably OK. I think the pleating thing is to make the snorkel less
annoying for divers, because it hangs better when you're not using it during
a dive.  (The use of a snorkel while scuba diving is a religious issue that
you probably don't care about, since you're just snorkeling.)

I recommend getting it in a bright color. I have the stealth black model,
and it's always getting lost in the dark recesses of my gear bag and in dark
dive lockers...

By the way, when you're comfortable snorkeling, try going out at night with
an underwater flashlight (you can rent them at the dive shop).  It's a whole
different world at night. You get to see the fish in their "pajamas",
sleeping under coral heads (really, some of them change color and pattern at
night).  Eels come out hunting, which it cool to watch.  And octopus & squid
are often spotted at night. Many resorts offer guided night snorkel trips. I
think it's cool to have someone tell you what you're seeing, especially
since the might reef is so different from the daytime reef.  Just ask the
locals whether you have to worry about jellyfish.

And don't forget to use sunscreen on your thighs & the backs of your ears.
I use a lycra skin for sun protection, but a friend of mine (female)
snorkels in an old pair of tights & a T-shirt.

Enjoy your trip!
Becky

If you decide not to buy your own stuff, see if you can rent it from a dive
shop in your town. They sometimes have better deals and you get to pick from
what's probably a better selection.