The rowboats are also very useful as well - pick up a few of them.
For one thing, they are temporary boats. When you use one, the deed stays in your pack. You don't have to retrieve it, as the deed can be reused and the placed rowboat goes away when you reuse it, or go too far from it. When I was doing trade orders, I would use it to go across from the mainland to Skara (since you can't use the ferry), or to Jhelom (about a minute by rowboat from the beach by Honor shrine), and it doesn't count as a "ship" for the trade order encounters.