Have the ship event on the maps with 2 tabs - tab 1 is unconditioned and shows the ship graphic, tab 2 uses a switch (we'll call it IN SHIP) and has no graphic. You'll actually have two of these - one in each location, and they'll use the same switch as the trigger.
When the player pays for the journey, let them "get on" the ship - when they trigger the ship event's action trigger, make them walk into the ship, change the player direction to the ship direction (if you can in 2K3), change the player graphic to the ship graphic, turn on the IN SHIP switch (so there's only one ship). Use a move route to get the player where you want them to go. When they arrive, do the reverse - turn off the IN SHIP switch so the ship reappears, change the player graphic back, make them move away from the ship.
My terminology is for XP. Hopefully you can do all these things in 2K3.