wingonwing, I was a professional muscian for many years so I'm not talking out of my butt.
Get an agent. Yes, you will have to pay them 10-15% but that motivates them to get you as much $$ as possible. The bonus is that you never have to fight with an owner when they short you your pay (and they will). You just hand the phone
to your agent.
I have several friends who did a few cruises on cruise ships. If you aren't a big drinker, since all of your expenses are paid except alcohol you canget a tidy bit of cash. If you have your boat moved to the port of the ship, pretty easy to do a few tours then return to your boat, cash in pocket. If you get in well with a bigger line, you can do a few tours out of one port, move your boat to the next port, then do a few more.
If you don't have a local following, you won't make very much money doing bar gigs. Why would the owners want to pay someone that nobody knows when they can play CDs for free?
I did bar gigs early on in my career- there is no money. Eventually, I moved forward enough to play large festivals. That is where the money is. Plenty of Festivals through out the Coastal US and in the Carribean. EWuropean Festivals used to be great for foreigners, now if you aren't EU its tougher.
Product sales will feed you on a cold night, you have to have good product and enough people in the audience to buy them. Once again- cruise ships and festivals. No way will you move enough product in a bar to be profitable, especially after you pay all the import fees
Cruise lines & Festivals, you'll need an agent to get into them but there's your answer.
Hope this helps.