If you are in Future World near the entrance, catch the bus that Tyler mentioned. If you are near the International gate, walk. If you're in the middle of the park, flip a coin.
If you leave on a boat at the same time that I start walking, I'll be waiting for you at the dock, eating an ice cream cone from Dinosaur Gerties. Those three resort stops take up a lot of time. And if you have to wait for a boat, I won't even bother waiting for you.