Rather would have airships and zepplins, so that you can also use it over the old content where you can fly.
But if ships happen i see them evolve into thoese two at the end of the exp pack.
Both are pretty mutch ships but with a airplain tech on them.
(ps i just hope we will not see the teleport system of Argus again, without any form of travel you remove like the whole feel and point of an open world game)