You sent me to this thread and asked me to comment on my success with WIFI in the islands. I have used a PCMCIA card (300 Milliwatt) very successfully. Eventually the little cable died, so I bought a replacement, this time the Alfa AWUSO36H, which uses two USB ports
on the computer and is 500 MW. I have a Hyperlink technologies 8.5db antenna which attached to the Alfa unit via a 20' low loss cable. I move the antenna around on the boat for the best reception- that pesky mast
seems to interfere. The farthest I've been able to reach is about 5 miles; That was reaching back to a harbor I had left (Little Harbor at the southern End of Abaco
Island) from Lubbers Quarters. I don't think I could pick up a new signal from 5 miles out, but 1 mile is not uncommon. I keep a spare Engenius adapter on board. From reading the cruising guides
for the Windwards & Leewards, it sounds like WIFI will be readily available there too, but maybe not for free....