Barefoot skiing...
Is water skiing behind a motorboat without the use of water skis,
commonly referred to as "barefooting". Barefooting requires the skier
to travel at higher speeds than conventional water skiing
(30-45mph/50-70kmh).
The necessary speed required to keep the skier upright varies by the
weight of the barefooter and can be approximated by the following
formula: (W / 10) + 20, where W is the skier's weight in pounds and the
result is in miles per hour. It is an act performed in show skiing, and on
its own.