Rollaboat

This boat would be shaped about like a football plus skeg. In general it would be designed to be watertight under dynamic water pressure from any direction. Propulsion and motor would be completely separable from the crew cabin. The crew cabin would be in an inner hull, and the inner hull would sit on ball bearings. Whichever way and however much the outer hull were to roll, the inner hull would maintain a relatively stable orientation. The submarine style hull would provide strong resistance to sinking. In stable water it would be possible to lock the inner hull to the outer to let windows work and provide handier ingress and egress. (With these unlinked one could open a hatch to an appropriately padded space in the outer hull and jump out. Getting into the inner hull would be a lot trickier)