If you're looking for something warmer try the Virgin Islands.
Specifically a few days on St. Thomas then one of the BVI's - either Tortola or Virgin Gorda. Fly into St. Thomas and fast ferry to the BVI's - about an hour to Tortola, 1-1/2 hrs. to Virgin Gorda.
St. Thomas has about a dozen wrecks just south of Charlotte Amalie and the BVI's have the Rhone - a two dive wreck that's one of the best.
Most of these are wrecks:
Blue Island Divers Dive SItes and many are shallow - 40'+. I don't know which are penetrable as we dove the reefs instead.
The
Rhone is a huge ship from the 1800's that broke apart off Salt Island. It sits about 70'. The front it penetrable - most of my group did it as there's lots of ways out. No one in our group was more than AOW at the time.
It's where they filmed The Deep with Jacqueline Bisset. The back is more flattened but there's some structure still remaining you can swim along/under. Also lots of big machinery on deck and the prop you can swim under - it's about 15' tall. It's the BVI's signature wreck shot - at one time it was featured in their travel ads.
I don't like wrecks and I liked this one. There's also a small plane wreck you can enter at Coral Gardens and enough other wrecks that DiveBVI has a wreck week package next May.
Wreck Week 2011 May 28 - June 4
All of the diving (17 dives) we did in a week were in less than 80'. And the water was swimsuit warm in late April.