anchor release underway

Interesting (and lucky) that's as far as it slipped. Years ago I was transporting a small boat across Great South Bay in about 3' real choppy seas when I saw the anchor head about 10' in the air. No safety lanyard. I held my breath as I waited to see if it would land on the deck or in my face. It came down and hooked on the bow rail like it was meant to be there.

Good place to leave it...

I was just a couple of days ahead of him. Got a face full of front running to impact Bertha. It got snotty out there in a hurry, and we were only about 50 miles from rounding Diamond out in the stream. We were followed by a brief calm the next day, but it was turning nasty on those heels. We got around and out just in time. Face full of fog. But I can certainly see how this can happen to a boat...and I'm addressing this now with a better long term solution to my simple synch through the chain that's wrapped around the capstan. That anchor takes a licking...

Nope. Still had half the bay to go. Crawled out and tied that sucker off. Surprised the crew of that other boat didn't do the same.

How did it deploy? No chain stopper, nothing securing the anchor ?

That's what I was wondering. Do larger vessels not secure the anchor or windlass in some fashion. Any windlass brake can fail, right?

Pascal, check your PM.

I've been the engineer on two different large yachts that this has happened to. Both times were an inexperienced mate that didn't lock the claw into the chain properly. Both times resulted in major downtime and repairs.
I won't get into details, but the first time the damage to the bow was so extensive the so called "captain" (and I use the term loosely) wanted to run the boat into shallow water (Bahamas) and abandon ship. Needless to say I didn't let him. Told him if he wanted to get off that bad I'd launch the tender for him. I brought the boat into port and did the repairs. He and the mate were both fired shortly after. That was over 30 yrs ago and the boat is still a South Florida staple today.
The second time the error was caught much earlier, with no external or structural damage. But we had to come to a dead stop in extremely rough Gulf Stream waters, to allow the windlass to retrieve the 3-400' of chain we were trailing. The interior suffered quite a bit of damage due to flying objects, like the galley refrigerator being torn out of the wall and emptying it's contents onto the floor, and the entire skylounge bar inventory shattering on the marble floor and saturating the new carpeting, yummm, smelled nice. So much shattered glass on two separate decks it was not safe to even attempt a clean up until we reached port. That was about 20 yrs ago and that boat is also still in service.

Exactly! I have a nice line and locking clip that secures mine quite securely.

1/2" is pretty common. Unfortunately they too often carry that filler down into the bottom paint. That's a recipe for a mess...fortunately on this photo it seems that you could long block the section of hull below the rail and remove most of that from the wetted surface during the repair.

I ran a 68' Chris aluminum Roamer. The only areas that never blistered were where there was plenty of filler. We had a complete paint and many blister repairs after, all on properly treated, etched, and primed paint. I often thought that the relatively thin layers of paint allowed micro-fissures to allow intrusion of moisture.

We were bringing our sailboat back across the Gulf of Mexico a few years ago, coming back from the Bahamas and I had a friend on board to help sail it. He called me up in the middle of the night on the passage, which was pretty sporty anyway, and told me the helm was just sluggish as it could be. After checking everything else, I walked up to the bow, and discovered the anchor had come loose and was hanging under the boat at the end of 200 feet of chain. Thank god we were in deep water!