I'm a bit curious on things. If I recall right, we are technically transporting Kaya to West Blue or Loguetown. Seeing as we just left Loguetown, then West Blue is the current end goal... How do we get there?
From what I remember of One Piece, all the Blues are separated from one another and only touch while entering into the Grand Line - which is a one way trip from all appearances of the Reverse Mountain and how they travel up it.
Do we have to make/buy/steal one of those Navy ships that are built to travel across the Calm Belts? But then again, Don Krieg somehow sailed his busted ship back from the Grand Line into the East Blue so... maybe he had all his men rowing to force the ship through the Calm Belt? Though Dracule Mihawk is able to get all over the place in his little personal boat somehow...
I think the only other way is to land on the Red Line, hike across to the piece of land that touches the right Blue, and board a new ship on that side.
I guess if you had the man power you could carry your ship across, but that would be a pretty brutal trek.