Note to anyone that finds themselves in a similar situation. While being towed sideways, the sails want to spin the bow toward the tow boat. With the tow boat pulling from the side, the loads are quite high (as evidence by the amount of throttle you can hear the RIB applying) The simplist and easiest way to right the boat with the least chance for damage is to tie the line to the front beam (center ... around the beam and to the mast post (between the bottom of the mast and the beam). Tow the turtled vessle backwards and into the wind if possible. It will come up like a porpoise.