I have a 2015 Bavaria 41. Over the weekend I noticed the head outflow seacock was leaking slightly, I tried to tighten it to no avail. I had the boat lifted this morning and when the yard were removing it the through hull skin fitting disintegrated. The yard were surprised to see a chrome outer skin fitting connected to brass seacock and said that it could have resulted in a catastrophic failure at any time. I dread to think what would have happened if I was at sea at the time. I have subsequently found out that the ISO standard says that they should last only 5 years. Needless to say I am having all below water skin fittings/seacocks replaced.
I strongly advise you to check yours!