The exhaust holes were open. I was expecting
water to exit those holes as it does in the Mark
7 I have. It looks to me as though water should
pass through this channel to cool the bearing
housing then down the exhaust housing. Looks
like the square nut has been replaced with a
locking tab.
Tubs
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.