I heard a hovercraft this morning, pretty sure they insure it, certainly has passengers.
Have heard rumours that they are looking to open up another route but I think its only seasonal and very infrequent. Hope it takes off though - pun not intended, but appreciated.
Never heard of a plane that managed to keep going without power and yet those can be insured. Also you can (apparently most do) make hovercraft with a buoyant hull.