NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Prop-walk.
From: Michael Dorl
Date: 2003 Apr 23, 08:06 -0500
From: Michael Dorl
Date: 2003 Apr 23, 08:06 -0500
I'm hesitant to pour more fuel on this discussion but here's what I was told.... In reverse, the prop throws a jet of water toward the hull of the boat. Because of the rotation, the jet is directed up on one side and down on the other. The upward directed portion acts more strongly on the hull hence it pushes the boat to one side. Once the boat starts moving, hydrodynamic forces over power these effects and they are not as pronounced. If this is true, one would expect keel boats to walk more than non keel boats. Not having much experience with big single prop boats, I don't know if that's true or not. the effect to be much more pronounced in reverse than in forward, seems to be the case for every boat I've had experience with