Chellyroo, I want to add my two cents on snorkle spots on St. John. We've been 12 times are very avid snorklers. You don't have to go off the beach to have a great snorkle experience. Anyway here are some of our favorites:
1 - Hawksnest - Very beautiful beach and looks of great elkhorn coral. Two long reefs that run perpendicular to the beach.
2 - Can't remember the name of the beach but park on peace hill & take the path to the small secluded beach. Great spot nobody goes to.
3 - Caneel Bay's main beach. That's right their main beach. Go to the right and around the corner. Lots of fish and nice coral.
4 - The island off Cinnamon Beach is great for small fish & tarpon.
5 - Waterlemon is very nice but a little harder to get to.
6 - Francis Bay is really good if you follow the shoreline to the right all the way toward Mary Point. It's long way but you are always close to the shore.
7 - Chocolate Hole - You must go all the way out to the point on the left side. Deeper depths close to shore and it's really cool.
8 - Reef Bay but you must go on a calm day or you will get beat up by the wave action.
9 - Haulover Bay - My favorite but again only attempt when seas are calm.
10 - Rainbow Beach is also very nice and an easy snorkle.

These are in no particular order and should keep you occupied for a week.

Have fun,
Mike

Bethml-- Wow, Akumal just moved up the list to the top two choices! That is awesome.

Pulley- I really appreciate those locations! We are torn right now between STJ and Akumal. One thing I notice looking on VRBO.com for lodging in STJ is that there doesn't seem to be anything ON the beach, most look to be up in the hills. That's not a deal killer, it's just nice to walk out the door into the ocean. Akumal seems to have a slew of afforadable, beachfront condos for around $150/nite (right up our alley). Thanks again for the info, my list for STJ is growing.

Only decently-priced oceanfront rental on St. John:
http://www.caribbeanvilla.com/calypso/calypso.html

Other than that, there are a few higher end rentals in Great Cruz Bay, but I can't remember the website that features them.

Also, a villa named "Siempre Azul" is waterfront, but I'm not sure if there's a sandy edge to the property.

STJ is not known for a lot of "Beachfront" accomodations other than Caneel or the Westin. The Westin beach is man-made, and not very desirable (IMO). Caneel is on some of the most beautiful beaches you've ever seen, but you'll pay big $$ to stay there.

STJ to me, is about getting in your jeep and exploring different beaches everyday. Driving around the island is an adventure in itself, and with a little effort, you'll be rewarded with some of the most uncrowded gorgeous beaches you've ever seen. If you are looking to stay on a long stretch of beach outside your door, STJ may not be the right choice.