John was really pushing things in about 20 knots of wind when a bigger squall hit him. One hull / rudder was already out of the water so the loading on the one hull via the foward drag of the spinnaker, was too much for the bouancy of the hull which promptly submerged virtually the whole hull. 20 knots of momentum slowing to a vitual stop in a few seconds means only one thing. No T foil would have prevented that capsize.