I'm no expert but have looked at A LOT of boats and getting them here. Hyde is the one who ships via sea from Miami and it cost a fortune, I forget how much but it's a lot! It's cheaper to hire a captain to sail it down which will be $5,000+US. Cuba, Cancun, Belize.
Duty has to be paid if your boat is here for longer then 30 days a pop, but you can always take it out of the country to avoid that.
Monohulls have a draft that's usually too deep here. You want 3' or less, unless you're staying outside of the reef. I've seen a few boats that have adjustable drafts, forget what it's called but they go from 2.5'-6'. Placencia and further south you see a lot more mono hulls as the reef is 20+ miles from the mainland, but there's still lots of coral around.