RC Sub
 

We are building an underwater camera and a rig to put it on and we are trying to find a servo that we can use underwater. Google is not helping right now so has anyone built an RC sub before?

I haven't built one, just seen a few in action.
Traxxas has a couple that are advertised as being waterproof but I don't know how well. Hi-tec is getting ready to release some new ones in both digital and analog with very good torque numbers, suitable enough for gas boat rudders easily. Check out www.hitecrcd.com .