Sadly most US moorings, other than on some of Maine's year round off-shore islands, are woefully inadequate for Nor'Easters or Cat 1, 2 or 3 hurricanes. Cat 4 or 5 all bets are off anyway. Our storm mooring was modeled after Maine's many off shore island year round moorings.
This is our boat on her storm mooring.
We are fortunate enough to have a storm mooring in front of our house in a fairly protected cove with only three or four other boats all spread out.. Our granite block is approx 14" thick, 8' long and 6' wide and weighs approx 9500 pounds. It is long, low and flat and has settled into the bottom so that only the 2" staple is showing. To change the bottom chain, once every 20 years or so, it requires diving as the largest mooring barge in the bay could not get it out of the mud.
For bottom chain we use 30' of USCG/US Navy surplus stud-link bottom chain. Each link is 10" long and it weighs approx 27 pounds per foot. For top chain we use 1" Acco long-link mooring chain & then on to a 1.5" Campbell eye to eye swivel. From there we have two Yale Polydyne 1" pendants, of unequal lengths, which are then connected to two 1" Dyneema storm pendants and one 1" Polydyne storm pendant. For chafe gear I use Chafe Pro... The cleats on our boat are backed by massive 1/2" thick G-10 plates.
Our regular mooring, around the point in Falmouth Foreside, is still pretty robust, especially for our boats size. It is likely more robust than perhaps 98% of the moorings in the US, but you could not pay me to keep our boat on it during a real storm.
This article may be of interest to some:
Mooring Preparation & Precaution For Storms (LINK)
Happily we've not had to put our storm mooring to a real test in years and I cross my fingers it stays that way..
