trimtab

the faster a vessel travels though a fluid medium, the higher the pressure against its control surfaces.
imagine the force against a rudder on a huge ocean ship as it speeds through the water.
it takes an enormous amount of force to turn the rudder at high speed.

as a much smaller control surface on the rudder, the trimtab requires much less force to move.
trimtab is technology for applying small shifts in direction toward a massive change of course.