broken propshaft

Agreed with the posts, there are so many factors and variables that its hard to pin point one possible source of failure, heck our previous boat was a 1989 38 ocean with 375 hp 3208 cats, that had 1 1/2" shafts with a 1.5:1 gear ratio. We owned and ran that boat from 2007- 2015 with no shaft issues with the original shafts. Now with this 2001 boat we have this issue, with supposedly more robust 2" shafts with a 2:1 ratio.

One thing is for certain, I will be having the shafts crack tested every haul out, which I aim to be every 2-3 years.

I am kicking myself a bit, I am a class surveyor and the classification rules state that crack testing should be performed on both ends of the propeller shaft at a minimum of every 5 years. So it looks like I should make sure to apply some of the class rules to my own vessel.

thanks again for all the help and I will let you know how it all goes.

Well I finally got my new shaft and prop 2 weeks ago and I hauled out last week Monday to make the swap. I pulled the port prop and did a dye check on the key way and all looked well, so fingers crossed. Overall the new shaft, coupling and reconditioned prop came to about $4000. with another $500. for the shipping to Trinidad. The prop shop did a great job of matching the new prop with the old one, as my speed went up a little bit and my rpm was in the same range as before. I would like to thank everyone here for their advice. One this is for sure that its good to have the boat back running after 6 weeks of down time

Some pics from the job

You are correct on that, the new shaft was shorter than the old one, which we thought was an issue at first, but it appears that it is the other way around. we measure and it is just about 1 " from the hub to the aft face of the strut, which is just about right for the 2" diameter shaft. next haul out, I might look at pulling out and shortening the port shaft to reduce the "whip"