Go for it! Take your time and consider an overnighter along the way - some good fishing and diving along the way - you don't want to just drive down there and miss the stuff in between that you can only see by boat... You can camp in a state park like Bahia Honda, or stay at one of the hotels that have docks and marinas. Could be a great trip.
Mike,Do it? Your Osprey will be fine. Hell, if you had a bow dodger, you could even camp on the boat, a little portable alcohol or butane stove stowed in the Haitian Hatch, sounds like fun!
Freshmen year of high school (Naples, 1977), my buddy's dad rents a place in Marathon, walks me and my buddy out to the 20' cc, and says "fill it up and head about 170 degrees off of Cape Romano. 3 hours later, look for Faro Blanco Marina....I'll meet you there".God looks out for fools and children...we were both. I don't even remember having a chart or a radio...just a compass. Oh yeah, and Dad's beer supply....which was considerably diminished by the time we arrived!Another wonderful Aquasport memory!