I actually developed (For T20) A new class of vehicle, called "Boards", that covered vehicles that you 'ride' rather than drive. Unlike other vehicle classes, as long as it's controls were set up similiarly, you could use the same feat (And the Ride skill, as opposed to the Drive skill), to ride grav boards, jet boards, hover boards, surf boards, skate boards, etc. Some types are self-powered, others used muscle power (As per the rules in "Through the Waves").