When Blue Opal launched this year, I opted to check all of the seacocks while she was still held in the slings. In doing so, I discovered a significant quantity of water in the space under the head, and it was salty. I called for a pause on the launching process while I checked it out – there was enough there that if there was an actual leak I should have seen and felt the water flowing in. I couldn’t, so we proceeded with the launch.
Some more investigation showed that the valve assembly that was mated to the through hull was definitely leaking slowly. I popped up to the office, and had a chat with the yard manager – he sent someone down to investigate (since they did the work the previous year to replace the old valve with a TruDesign one). The guy arrived, and I said it’d be fine if the valve handle was pointing down a bit; it’s much easier to operate than the 90-degree type.
A few minutes later, and he’d put a whole turn and a quarter on the fitting. The conclusion was that the installation process might have had a mis-count; they fit the valve on, counting rotations, back it all the way off, put on the sealant gunk, and then twist it back on while counting the turns. Off-by-one would be very possible. Given I’d not seen water from it all year, it’s possible that when I turned the valve on and off to test it (while Blue Opal was in the water over winter) I twisted the whole fitting just enough to cause a slow leak.
No water has been found under the heads since launching in April.