: Planning amas (outrigger floats) don't work, the heeling moment
: from the main hull forces the hull into the water so it won't
: rise up on top on a plane. Long skinny amas work much better.
: How well a sailing canoe/kayak turns depends much on the bottom
: shape. Those with long straight keels turn slowly, not all have
: those shape though and most turn (tack) very easily.

: Bill H.

True about the planing float. However, for any float type I would try to keep the float out of the water for best speed. That is easier in a canoe - which is what I was thinking about at the time - than in the narrow cockpit of a kayak, for which the long skinny ama would be the way to go. The planing ama has more reserve bouyancy for a given amount of material and weight than a skinny design and would take up less space for storage and transport.

Probably the ideal design for a kayak ama would be almost as long as the kayak with a narrow bottom for lowest resistance when slightly immersed and significantly flared sheers to increase the displacement rapidly if it is forced down by a gust. That is what I have seen on modern trimaran designs. In my experience an ama with a lot of down-force on it creates a lot of drag.