Collision

Yes I know there are loads of posts about collision detection, but I have not been able to find one that answers my problem.

I have to make a game for school. I am making a flight sim, where your plane starts on an aircraft carrier. I got the collision working for the ground, but how can I get it to work for the carrier? The only thing I can think of is to use boxes, since the carrier is such an odd shape, but I still can't get it working.

Would appreciate your help ASAP, as I only have a few days to figure this out.

Thanks

PS. If you need my file, I can post it.

EDIT: I have a way of doing it, but it is not very effective, and I would still like to know if there is a betetr way