I was thinking of my next one that will be big enough to do that comfortably and safely. I was also thinking of a trawler type of boat, slow, heavy, but with great fuel efficiency and roomy, so something in the 35-foot range. You can do it with smaller but I'm talking about having protected "saloon", bathroom, kitchenette, AC, etc. The FL to Bahamas is 50 miles. Sailing and trawlers/tugs boats go about 5-7 knots (6-8mph), depending on current which can be up to 2 mph, burning 1.5-3.5 gph, where speed boats can go 25-40 mph, but they burn 20-60 gph (that's gallons per hour).
My 21footer burns .75gph at 7-8 mph, inboard diesel engine. I can push it to 10-12mph. It's great for day trips, rivers, lakes, near coast.