The tunnel hull is a strange ‘bird’. while the tunnel derives much of its high performance from air lift, it depends at the same time on its planing interaction with. Tunnel hull 15: a family line of high performance tunnel hulls, designed to move out in all water conditions at all speeds. wide transom and deep tunnel make for. The hull is about more than just good looks. the shape of the hull affects the speed, stability, and maneuverability of the rc boat. flat-bottom, monoplane.