If you want to get navigation, you'll need 12,000 doubloons. Go to the parrot port and all the way to your right, the last place you see, go there. Then on the top floor, there's a girl with red hair. Click her. She's your navigator. I don't know how to get a bigger boat. If you know, erase this answer and put it up!! :)
After you have traded on the raft for awhile, and have 3000 doubloons, you can buy the next larger ship, the Jimmy Rigger, at the Ship Shape shipbuilders at Dragon Cove. As you collect more doubloons, you can buy even larger ships and hire the skilled crewmen to improve their performance.
You actually can have less than you need to buy a bigger ship, because you can borrow up to your current worth from the bank at Golden Harbor. (You must repay the loan before you can get another loan.)
go to the dragon cove and go all the way to the right
Once you've gotten to the Japanese island you go to the guy selling ships and if you have enough money you can buy a bigger ship.
When you earn or borrow enough doubloons, the shipbuilder is at Dragon Cove just past the trading post.
Just dock in an island and your ship (or raft) will fully heal.
The cannons on your ship!
You go into any harbor.
No. To sail a ship, go to Skullduggery Island.
You can trade your ship in when you buy a larger one.
you have to get doubloons by trading grain silk medicine and spice (go around all of the islands on skullduggery)
You repair your ship by pulling into any harbor. You can upgrade your ship at the ship builder's at Dragon Cove.
you dive to were your ship(raft)is and you swim till you get to sand
The only ship you go on is your own. You begin with the raft and you buy larger ships as you can afford them.