USVI vs St.Lucia vs Caymans

If you loved the dramatic undulating, volcanic topography of Hawaii you would love St Lucia. check out the Jalousie Plantation which sits on 192 acres in the embrace of the island's world heritage-listed Pitons. The new luxury villas (with butler service and private plunge pools)are stunning and the surroundings really world class. There's a national marine reserve right off the white sand beach (the snorkelling is great) and an excellent PADI dive centre too. the hotel offers a free beach dive per day for qualified divers and a free try-dive for beginners. The property is going to be rebranded and relaunched as The Tides Sugar Beach towards the end of next year, but in February 2010 you will be able to have a taste of the ultra-swanky Tides experience (including amazing tasting menus in the Great Room)for a fraction of the cost. The website (www.thejalousieplantation.com) doesn't really do the location or the new rooms justice. I understand they will be updated their images shortly.
This is the perfect base from which to climb the Gros Piton or visit the sulphur springs and volcano. The lovliest thing about St Lucia are the St Lucians themselves... they are warm and genuinely friendly. There is excellent direct airlift from both the UK (British Airways, Virgin) and the US (American Airlines, Delta, Jet Blue starting in October 2009).

I've been to the 3 places you're interested in, and I agree with mollymcdee if you're looking for a place similar to Hawaii. Jalousie is beautiful

First of all, Jalousie Plantation is scheduled to close and will probably not be reopened by February (though I'm not sure of the dates). But St. Lucia or St. John will probably give you the most Hawaii-like experience in the Caribbean.

Any of the islands has good snorkeling, but St. Lucia doesn't have the same beautiful white-sand beaches as many of the other islands. Also include the British Virgin Islands in your search. You might find them more to your liking. In the USVI, only St. Thomas has anything approaching an overly developed tourism infrastructure. Grand Cayman is certainly developed, but it's certainly no more touristy than Hawaii. You don't say where you stayed in Hawaii, but perhaps it was Kauai, and then you might find some of these islands over-developed. But otherwise, I think you won't.

Jalousie Plantation is DEFINITELY open in February 2010. It will NOT be closing until the late summer. There had been plans to close it this year, but with 192 acres to play with and with the rooms in separate "clusters" they decided to keep it open and only close for a few months next year to do the main pool.

grand cayman is not lush at all. it does have very good off beach snorkeling with uber clear water. for quiet you might take a look at the reef or morrit's resorts - both on the east end of grand cayman away from the hubbub, but within 45 min drive of town/shopping/more restaurants/etc.
grand cayman is generally speaking too expensive for spring breakers so that should not be an issue if you choose to stay on seven mile beach (which is the main attraction and a very nice beach on gc). some very good dining options.

i do not agree that all islands have good snorkeling. st. lucia is definitely not known for it, but there is some. it is a lush hilly island so may look like hawaii. they have a zip line & drive through volcano, good hiking in rain forest. it is a large island and not all that easy to get around - many ppl use water taxis rather than overland routes.

i'd look at st. john, usvi. very good snorkeling options from lots of beaches. caneel bay resort (has 7 of it's own beaches) would be optimal but it is rustic sheek - no tv in rooms. plenty of restaurants and easy access to st. thomas for shopping, etc.
or on virgin gorda either little dix bay or biras creek. not many dining options on virgin gorda though. good snorkeling.