Hey Guys --
My experience has been that the skills needed in the low-speed handling of a conventional outboard or outdrive boat translate nicely to those required for outboard-equipped Mac under power. Much more so than to other inboard sailboats, which, because of a variety of other prop/rudder configurations, require another, somewhat different skill set. The use of prop walk is one of those skills that can be used on our Macs.
Prop walk is a sum of a lot of interacting factors, at least one of which I have considered myself and not read or heard anywhere else.
The difference in angle of attack between the upward moving, and downward moving blades resulting from the angle of the driveshaft, while the most familiar and most often cited, is only one of many sources of prop walk.
Outboard engines experience prop walk mostly from sources other than this. I use prop walk every time I back out from my slip and it’s a breeze, (even when there is a cross-breeze). Plan your movements so you are always backing to port. (I happen to prefer ballast in, ~25- 50 % dagger or centerboard, and rudder(s) down).
You can demonstrate it to yourself on your own boat. Centre your steering out on the open water while stopped, and apply reverse thrust, with a good quick burst. With any conventional engine/prop configuration your stern will pull or “kick” to port. Use this to your advantage when manoeuvering. It can be your friend, or your enemy, it can surreptitiously make a fool out of you in close quarters or in an emergency; it’s your choice, but ignore it at your peril.
The pilots on this forum will recognize this as “p-factor”, the term for it in aviation. You cannot ignore it on a small airplane (as you might possibly on a boat)- during full-throttle climbout you need to apply right rudder to keep the plane on a straight heading.
Back on the lake, apply heavy throttle forward and your stern will kick to starboard, but to a much lesser degree than reverse because the lower unit and prop design have been optimized for forward movement, and the slipstream has no opportunity to interact with the hull or keel.
If you ever need to make a minimum radius turn, say in a narrow channel or fairway, you will require less width if you turn to starboard, using the automotive equivalent of a three-point turn. This recommendation applies to all conventional (right-hand prop) power boats and Macs.
It’s called “walk” because the stern’s movement is in a direction that it would take if the prop where “walking” on, or contacting the lake bottom. So that little tidbit will help you if you are in a boat and trying to visualize which way yer butt’s gonna get kicked.