Thanks Mr. T for your detailed and informative reply. I posted a similar question at the International Hydrofoil Society website and will post any replies to that here. Some skippers use only one board or both all the (upwind) time, while others use two boards in light airs and only one in heavy going. Similarly, some skippers swear that the best way to motor a cat is with both motors going full time while others say using one at a time (assuming folding/feathering props) is the most efficient. My intuition would be that the single board & engine would be the most efficient. Any thoughts out there? --------------------------------- It's here! Your new message! Get new email alerts with the free Yahoo! Toolbar.