The invention concerns an underframe with controlled deformation for a gliding craft, in particular for a skateboard, characterised in that it comprises a structure with a central platform, a front platform and a rear platform, the platforms comprising a box-type arrangement with a pressure surface and a suction surface. Via a feed line a fluid may be supplied under pressure to and removed from the fluid chamber, wherein provided between the fluid chamber and the feed line is a valve arrangement, which closes when the pressure in the feed line drops below a minimum value and opens when the pressure exceeds the minimum value. The inclusion of tilt sensor provides an enhanced paint ball gun capable of operating optimally during periods of gun tilt.