thru hulls
I was a little luckier...ok a lot luckier. When I had an survey, about 6 years ago, the surveyor found the same thru hull cracked. I replaced it with a bronze one, new hose to the sink and then he also required me to double clamp everything below the waterline and recommended everything above. I did. The following fall, I went to remove the raw water intake hose that goes to the engine to add some grease to it. I barely touched the thing and it fell apart. I could have farted on it and it would have crumbled. Given that, every one of my thru hulls has been replaced or very thoroughly gone over (with a hammer) to insure integrity. I took my thru hull set up to the chandlery and the guys there kinda laughed and said "you would think these things would last more than 20 years..." Sorry about the loss it is a really dumb place for the sink thru hull when it could have been just as easily plumbed to the shower sump.