Ferry service - Some kind of boat service that carries travelers from Arkham to Hamsah to Seantryn Modan and vice versa. Ferries would travel slowly and be able to be boarded while in route. Though this would entail the ferry guards to try to repel them. Maybe even one between Tar Valon and Galadon as well.

P.S. And for the love of all that's evil a damned boat seller in Tar Valon! ;) The city is an island, there should be someone who sells boats there.