Anyone looking to do some Giant tuna fishing this year should check out
http://www.fishermansoutfitter.com/t-bluefin.aspx These guys have been outfitting tuna in gloucester and cape cod mass where giant tuna has been the main deal for the past 3 decades. They have alot of information about chunking/chumming for bluefin and trolling as well.
Sight fishing is pretty easy in the clear water of the Bahamas, but coaxing these fish to bite could be tricky especially with all of the byctach that is ready to devour your expensive lures and spreaders. I would recommend calling Fisherman's Outfitter about what tackle might be worthwhile. Anchoring and chumming is usually only effective when the fish are settled in up in Mass, but the Bahamas fish may be too much on the run for that to work. Whatever, if the Bahamas Bluefin run is going to beocme a thing again, I sure would like to get in on it. Larger fish should be released as the commerical season is closed and there really is no reason to keep a large fish. A smaller one (under 250) may make alot of good sashimi though.