Some additional thoughts from a fellow New Englander (greater Boston). I've been to CCV twice (both in March = 2012, 2013) and am booked again for March 2014. Both trips were with my daughter (15 on first trip; she'll be 17 when we go in 2014). She was newly certified in 2012 and did her OW check-out/cert. dives at CCV at the beginning of our first trip. I've been diving since 2000, with about 350 total dives.
If you like relaxed....CCV delivers that in spades, both above and under water. You can dive as much or as little as you want....boat, shore, night, day, etc. The dive logistics are great = well organized, secure storage; self service tanks available for shore diving 24/7; great quality shore diving located about 100 yards from where you gear up inside the dive "locker rooms" (sort of like open air garages where all your gear is kept during the week); some of most easily navigable shore diving you'll ever find without sacrificing quality (with "yellow brick road"-like navigation aids directing you to the wreck on the house reef and the 2 adjacent walls); 2 mooring boat dives and 2 drop-off boat dives offered each day; great place for trying night diving (my daughter is hooked on night diving after trying it at CCV); well-run boats with great captains and in-water DMs (all with long tenure at CCV). We've had GREAT experiences with the DMs and instructor staff at CCV..I felt like they were always keeping an eye on us.....without being over-involved babysitters. They seem to do a good job assessing your dive abilities and giving you the requisite attention
Currents = have experienced only very mild current in my "vast" 2 trip experience. Shark dive is available, but provided via a non-CCV operator well away from CCV boat sites....otherwise shark sitings seem to be rare.
Above the water, 3 bathing suits and enough t shirts for a week is about all you need. Very relaxed "dive camp" atmosphere. Buffet meals - nothing gourmet, but wholesome and plenty of food. Daughter is a vegetarian and the kitchen staff has always taken good care of her. Lots of like-minded divers...met so many nice folks there. You are somewhat captive at the resort and CCV is completely dive/snorkel oriented (no TVS, pool, etc.)....so if you are looking for non-dive distractions, CCV will not deliver that.
Diving depths = My daughter has never been deeper than 60 feet at CCV...never a problem given that almost all of the boat dives are wall dives, with the top of the reef in 15-25 feet of water. You can safely choose any depth you want.
Flights = we've used BOS-ATL-RTB on both of our trips and we'll use this route again in 2014 (Delta). As with any airline trip, pricing from Logan really depends on time of year and how far in advance you purchase. In March we've paid $650-$800 per person. We've always traveled Sat-Sat. Not sure if you can find better rates from Portland or Manchester, NH.
We've chosen March since it is when daughter has school vacation. We've been blessed with good conditions, a little rain in 2013. Water temps were 79-80F both years.
Medications = we've taken Malerone for malaria on both trips and will do this again in 2014. Malaria is not a high likelihood, but better safe than sorry and felt confident taking it since we had taken Malerone during trips to Africa with neither of us experiencing adverse side effects (touching wood). Bug spray is a MUST!!!