Book - magician, topic - Bas Tyra

Hi everyone,
I'm new to this forum so if I do something wrong - i'm really sorry in advance.
Anyways I've read the serpentwar saga and have now gone back and started reading the riftwar saga. I've just finished Magician and something's bugging me. When Bas Tyra arrived in Krondor he had his ship with him, what I don't understand is how he got it there? When I look at the maps of Midkemia at the start of the book, it doesn't indicate whether there is a sea under great Kesh or above the Northlands. Can someone please tell me how he got his gigantic warship from Bas Tyra in the Kingdom sea to Krondor in the Bitter sea?
Thanks very much.
Court.