you can get beach towels for your stay in the monkey business shop at BB...you sign them out...only pay if you lose them!
they have little bars of soap in the bathrooms...that's it.
6 days is NOT long enough! you'll want to stay forever! we did 10 days...barely long enough for a vacation...but any time is better than none!
i believe all the snorkel trips will have life vests/belts...i brought my own inflatable...much more comfortable...
have a great time! no doubts!