Sean - I know - nothing like 82 F top to bottom and 100+ visibility! I'm not convinced I'll even enjoy diving here in RI, but I won't know until I try it, right?
Orion - I live in south county, and I have no gear for our water temps. I'd pretty much need to rent everything except maybe my regulator to dive here. My BC is a super slim, meant-for-traveling and warm-water-diving, that won't even hold the weight I'd need here. I'd love to hear recommendations about dive shops to look into for rentals.
your mask and snorkel will be fine. also, if you are any good with weighting yourself and buoyancy control you BC should work - wetsuites do not compress that much, especially if you don't go deep; drysuits allow for inflation so no issue there. If you plan to do more than an occasional, planned dive i'd advise to get yourself at least one tank, preferably steel; if you have a decent RMV than you should be able to get away with an LP72 (i do, though i tend to grab an LP104 since the price of the fill is almost identical and i get twice the bottom time), plenty of them around and most of them cheap as dirt.
inlandivers in leicester, ma has some brand new equipment on sale, check the closeouts at inlandivers.com, prices seem decent (i haven't bought anything in the last 2 years so my definition of decent might be off).
the regulator will be fine as long as you have a decent middle of the line unit from a reputable manufacturer, i dive a mares abys or an old USD conshhelf and both are just fine, regardless of the weather. get some decent size fins if you don't have them, sometimes there's current out there, not always when and where you expect it.
also, keep an eye on craiglist for some weights, you can find them sometimes for less than your daily coffee.
that would be about all regarding equipment.
i don't dive RI too much (mostly for weatherill) but there's plenty of diving spots just a little north in MA, starting with white horse beach (and surroundings) and continuing to cape ann. also, there's plenty of nice dive spots that are accessible by boat only (out of question until weather warm up, at least for me). you should see the "lobster colony" off Salisbury MA, ....