As one person suggested, you can contact the
marinas for info by using your VHF.
As far as telephone service, we spent two months last year, working down thru
Bimini, Berry Islands, and the Exumas. Signed up for Sprint Global Roaming prior to the trip. In addition to our regular US plan costs, we made voice calls for $0.20 per minute, and had free unlimited texting, and free 3G data service. We had good
reception everywhere except in the Land and Sea Park - where there are no Batelco towers (so no one else gets
reception their either). Regardless of the horror stories people had, we were charged nothing else. We had Sprint unlock our phones prior to departure just in case of problems with the Global Roaming Plan, then we could get the Batelco sim cards. Never bothered with sim cards.
We were shocked at how much connectivity we had, and how
cheap. It was most times better reception than I get at my house in Port Aransas. 3G is not fast, and you won't be watching videos with it, but so what. It was free. Texting was as fast as it is in the states, including sending pictures.
I have no ties to Sprint. But was very happy with them on this trip. Why screw with trying to find a Batelco sim card? (Our friends went that
route, and had to do a lot of walking around in
Bimini to find someone with sim cards, and eventually gave up, waiting to get one in Georgetown!). And paying $0.99 per minute for Batelco? OTOH, if for some reason you need 4G service, not sure if Sprint could deliver that. But who goes to Bahamas to play on the internet!