I would like to see the ability to "tow" a raft, rowboat, or sailboat put in the game. Imagine I am selling a Knarr to someone on another server, upon arrival I will have 6 silver in my pocket and no way to get home unless I have an alt which must have subscription given the body control requirements of boats, use 1000 karma per sale, or bring a friend who would much rather do something else other than spend hours facilitating his friends business delivery. I would say this is a silly, unnecessary handicap on shipbuilders. We have a "lead" mechanic for animals, a "drag mechanic" for other things. This I think is reasonable and not game breaking, you could make it so the other ship must be empty if there are any concerns over that. Thank you!
Edit: I think John's Idea of Loading, instead of or in addition to towing or leading is the best option. This would also make it easier to cross from one server to another with the second vessel.