Approach and takeoff drills need no pit at all
A marked takeoff point on any runway, track, or flat stretch of pavement lets you drill your full approach and the plant at the board without ever leaving the ground. This is also where the most correctable errors live, since approach inconsistency costs more distance than a flight-technique flaw for most jumpers below elite level. Six reps a session, focused entirely on hitting the mark cleanly, does more for a jumper's actual competition distance than another week of flight-technique work ever will.

