Not many things will ruin your day on the water like losinga propeller shaft.  We once backed down underpower to spin some grass off the props and had one of the shafts slip out ofits coupling.  Thankfully, there was azinc nut on the shaft that kept it under the boat, but it wasn’t in the boat,and there was a large hole in the hull where it was supposed to be.  These types of things are typical fordelivery trips, but not really something you ever want to happen if you canhelp it.

So the Shaft Retention Collar from PYI seemed like cheapinsurance.  And they were easy to put on,even with my ridiculously tight bilges. 
Getting a picture was tough, though. 
There isn’t much room to swing a camera, much less a wrench. 

I placed them right up against the couplings so any movementwould be apparent.  If the shaft comesfree, it will slide back until the collar hits the shaft seal.  Ideally I want enough space between thecollar and the shaft seal so the shaft can completely exit the coupling.  This would let the prop freewheel,drastically reducing the pulling force against the collar and letting the helmsmanknow something was wrong. 

Unfortunately, I don’t have that much room.  I will only know if the coupling has failedby making visual checks, or until the collar lets go too, probably making thecollar pointless in my case.  I shouldhave had the shafts through-bolted to the couplings the last time they werepulled, but didn’t think of it.

The shaft seals are new and quite a bit bigger than the oneswe had during the delivery fiasco.  Lookingat the picture above, I suddenly realized that if I do lose another shaft I’m goingto have a hell of a time getting a plug in there.