A single prop, or twins turning the same rotation should produce little prop walk effect going ahead. It's noticeable in many boats going astern, since the prop wash does not flow over the rudder(s). Prop walk (in reverse) is not as bad in longer boats with long keels or small props. Au contraire, short stubby boats with no keels (Springers) just wander where they want to in reverse.
To illustrate further what I said in my earlier post: Imagine wanting to spin a boat with 2 outward turning props in its length to port. Put the rudder partway to the left and starboard engine ahead, port astern. Now both props are turning clockwise (as seen from astern), so the bottom blades are moving to the left, pushing more water to the left, and moving the stern to the right (PROP WALK). This adds to the force of the starboard engine pushing water against its rudder while the port engine's main thrust is pulling the boat around to the left.
If the props were set up to spin inward, the prop walk goes against the desired spin of the boat to port.
Prop walk can be used in close in maneuvering, as in docking. Take a single screw, left hand prop boat. Approaching a dock on the starboard side at a small angle, as the boat nears the dock, give the engine a small bump astern and watch the prop walk snug the stern to the right and into the dock.
