Glad to hear so many Sailnetters came through the storm so well.
Yesterday I went out to the boat and she was exactly where and how I left her. Aside from a coating of salt and a few bits of seaweed here and there, it was difficult to find any evidence that she'd been through 45-50 kt sustained winds for 6+ hours and higher gusts. Seas in the harbor were running 4-5 ft at times.
The mooring set up I used was three pendants to the ball: two 1" x 20 ft made up by Yale Cordage, and one 1" three strand nylon I made up a number of years ago. Each of these was set with about 12-18" of slack differnetial between them. As the "fail safe" device I shackled the boat's 1/2" anchor rode to the mooring top chain below the ball and swivel. I left the chain with about 5-6 ft of slack relative to the slackest of the pendants. I lashed them all to the bow rollers in much the same way shown in Bene505 pictures above.
All pendants had good chafeing gear.
The anchor rode with 5+ ft of slack was wrapped around the bollard and then wrapped completely around a cleat on the deck such that the chain was pretty well jammed and couldn't put any pressure on the windlass.
The only thing that was different when I stepped aboard the boat yesterday was that the chain was really jammed into the cleat. It took some doing to release it. That tells me that at some point the chain took a heavy load -- so much so that it chipped the paint below the cleat in several places. That means that the rodes (all 20-23 ft) stretched at least 5 ft and possibly more-- without breaking.
I reviewed all this with a salty old commercial fisherman who happened by and he had two suggestions on improvements for "next time":
1. He said I might consider shackleing the chain rode to the bottom chain rather than to the ball so that if the top chain parted I'd have the reduncancy I was looking for. Or as an alternative to that dropping an anchor a few feet away from the boat.
2. I should have used short snubbers on the chain rode even though it was the last line of defense and had a lot of slack in it. He suggested making up two snubbers of slightly different lengths and diameters, with the smaller diameter the longer of the two. That way the smaller of the two stretches first and farthest, but the larger takes a load as soon as the smaller of the snubbers has stretched 10-15% of its length. He recommended two snubbers for redundancy.
Both of these suggestions are on my to do list for the next storm, but first on the list for next time is getting the hell out of the water!
Three sailboats came up on the beach in Provincetown. None damaged seriously and all due to pendant chafe. All still had sails bent on, one with it's jib still on the furler partially shredded. Obvious lessons here are better chafe gear and removal of all canvas.
One more thing: I rigged an anchor with nylon rode and chain and laid it all out in the cockpit in case the boat went on the beach and an anchor was needed by anyone who might come to her rescue.
As it happened one of the three beached boats mentioned above was saved from going hard on the beach because we were able to find an anchor in the forward locker. Working in thigh deep water / surf at dead low tide, it took some doing to get it untangled and deployed, but we finally did get it set. That said it was a pretty light rode/anchor for a boat in a storm -- looked more like a lunch hook. As the tide rose and the boat started floating again the anchor held. On the first high tide after the storm the boat was towed to it's mooring without difficulty.
I would recommend to anyone who leaves a boat on a storm mooring to help out those who might help you by getting a good storm anchor and having it ready for rescuers to deploy quickly.