Bright Water has a great big propeller. It works great when we’re running the motor- we don’t slow down when we hit waves, we get good economy, and it’s easy to maneuver and back up in marinas.
But when we’re sailing, the prop free-wheels. It’s loud and it’s likely that it slows the boat down (think helicopter auto-rotation).
So my buddy Jim talked me into trying something we’ve discussed for a long time.
We tied four feet of old 7/16″ stayset line to a 5/8″ x 3/4″ teak stick, put the stick over the shaft, and wrapped the line around the 1-1/2″ shaft. We could stop the prop with three wraps. So I put on six and then pulled a loop into the last wrap. The last wrap never drew tight.
It worked perfectly on our not-very-windy day up to five knots. We’ll see where the stick snaps. If it works at 12 knots I’ll be surprised. I think that teak stick will snap like a twig. I’d rather have the stick break than something else, though.
Follow-up: It exploded at 7-8 knots, and the flying pieces threatened to tear the hose fittings off the shaft seal (and, you know, sink the boat). More consideration is required. Perhaps a calculation or two. Another issue is that the transmission fluid doesn’t circulate while free-wheeling, and the transmission got up to 150F. That’s 50 degrees hotter than while running, but not too hot. Engine oil runs at 230-250 all the time.