George, I hear ya on the chaining of the stands, and many people up on the Rondout do exactly that. But in the case of Sandy I think these guys were right, the water came up so high it simply floated the boats straight up and off. The peak high tide at Poughkeepsie was 9.5 feet above normal. At that height its a miracle any boat was left on the stands, chains or no.
I decided last weekend that the best course of action was to let the boat "sink" - meaning leave the plugs out, hope the flooding was gradual enough that the boat filled with water, weighed down and stayed on the stands, and thats exactly what happened with my boat yesterday. My plan would have been perfect - I measured today and figure that a Hurricane Irene storm surge would have stayed beneath my cabin floorboards and drained back out of the bilge when the tide receded. Well that was so.... 2011. This was Sandy, some 1.5 feet higher than Irene, so I got about 8" of water over my cabin sole. Still, considering what these guys are all dealing with, I am grateful...