I think I might have to explain this one.

I've noticed in recent Pokemon games,( as recent as Ruby, Sapphire, and Emerald) that if you're surfing somewhere and you abruptly have to fly to some random city, the Pokemon that you're surfing gets left behind as you fly away.

What an excellent way on becoming the world's greatest Pokemon Trainer while abandoning a member of your team in the middle of the sea.

If I was the Gyarados, I would swim away~