The tow segment through the no-wind marina entrance was embarrassing (thanks so much to the runabout that almost passed me!), but once we got to the closest dock, I was able to pick up an active fender (also known as crew); we had a nice downwind leg in 3k wind and then turn into my slip. Thankfully, the appreciative audience missed the first part (most of those transients MOTORED
down from Portland, so they should applaud).
But here’s the deal: Engine fine, prop shaft turns in forward & reverse (observed at the stuffing box), but no propulsion. The propeller is present, but does not spin.
This is an Islander 28 with a 3/4” prop shaft and 3 blade fixed prop. Location is lower Columbia River (30 miles to nearest haul-out facilities)
I suspect the prop retaining knots came loose (cotter pin gone?) and/or the prop/prop-shaft key has corroded or fallen out. (I am hoping it is not terminal galvanic corrosion.)
A sailing friend with scuba gear (and wetsuit) will dive to check it out. I’d like to be prepared ahead of time if possible: meaning have a prop/prop shaft key & nut cotter pin available; zinc's too. What else?
BTW, I did do a search before posting. Closest I’ve come is the thread on “Changing Prop Underwater” (March 2007) and I’ve printed the blow-by-blow how-to (thanks, Fstbttms). Also noted is Sue & Larry’s “pulling propellers” (March 2002).
So, FINALLY THE QUESTION: Can I determine ahead of time what size key is likely to be needed; and/or what range of sizes should I get? If not, what do I do next?