Tom, thanks for reminding all of us that awareness of the surface of the water and the sky are things we should aways be very wary of. Several times I have been caught in wind squalls which arrived at a speed of over 50 knots traveling over the water, and had velocities much higher.
One time we were at San Miquel Island, when a white squall came off the beach--I had just hoisted the mizzen sail, on a 62 foot ketch (about 20% of the normal sail area) at anchor. I saw it coming, and yelled for everyone to hang on--the boat heeled over at more than 60 degrees.
Another time on the River Elbe in Germany, we saw the squall approaching--and I yelled at my son to get the main off, while I pulled in the roller furling of a genoa. We saw this coming at least 5 miles away--my son got the sail down--but I didn't get the genoa in fast enough--and we shreded the last 3 feet of the leach of that sail. Other boats had all of their sails blow out--and even freighters were blow out of the channel onto shoals in seconds. We had the engine running, and found a bouy, which we kept the bow right next to, so we were not driven aground.