Set up the boat:

Boats can be bought from shipwright NPCs in deeds, which should be used near seas, to build the true boat. The boat position must be in water. Boats cannot pass under bridges!

When the ship is created, a key will automatically bounce in your backpack . With that you can lock and unlock your boat.

To enter or exit the boat, just double-click on any side of it, to let the plank open (double click to close it). TO exit open the plank and walk on it.

Each player on the boat can lead it, everyone can enter, if the planks are open.

Boats can load stuff, just put it into the prow box. Is possible to put any amount of stuff in your boat, but if you do, you must be on the boat.

I would like to change my ship's name

You can obviously change your ship's name, just double-click the tillerman. You can also remove the ship's name, saying "Remove name" to the tillerman.