It would seem to be a farily simple task to put a bipod mast, set well aft (which would be easy to take up and down and be short rigged/lying on the deck when necessary) on a number of power cats. This would allow the use of one or two asymetical spinakers for reaching or down wind use without major modification of the hulls. The rig could be short and used for extending the range, or slow speed propulsion if loss of primary power. The sail kite also is a possibility--but this seems like it might be more difficult to control. Bob Austin