Japaneese Ship

I'm on the half sunken Japannes ship in the Lagoon level. I'm at the point where I have to swin from the aft of the ship to the stern to get the key. But I can't get close to making it back and forth before I drown. Am I missing something? Also, where can I find a walkthrough for the whole game?

[nd]

What you are trying is impossible. Instead, make sure you have that rusty hammer (if not, it is easy to find from where you are).

Then take a deep breath and go all the way to the place where the key is. BUT: one crosspoint before you go down to that place turn right and immediately left where a ladder leads up (maybe it could help using the map). Go up there and use the hammer on the lock. From there, you can take a second dive to get the key.

You find a walkthrough at http://www.canofworms.com/game/indy/index.htm - but think twice before you use it because you'll be much more satisfied if you solve the game youself.

Thanks, I was wondering what that hammer was for.