The idea behind a variable pitch prop is
you keep the engine at a fixed rpm and
adjust the pitch to control your speed.

For reverse, you reverse the pitch so
docking is much easier. You would only
use your reverse in your transmission to
chose the "prop-walk" direction, for docking.

"STABU" wrote
You should consider a Brunton Weill AUTOPROP. I Have had 2 on different
vessels a Fisher 25 and a Fisher 30. You do not need any controls.They
automatically assume the correct pitch.