Harbor
At the Harbor, you can find the following options:
Set Sail
Choose this option to sail the ocean.
Upgrade Boat
Use 
Barrels/Barris to improve your vessel's status.
Cargo Hold
Add 
Fishing Poles or 
Bombs to the cargo hold for use during your maritime adventure.
Skins
Change your boat's appearance. You can buy new skins from the Ticket Shop and the Diamond Shop.