We use to own a 50' canoe stern wooden boat that came with batwings as they are called. They were plates 1/2" thick that were on struts bolted straight out from the bottom of the keel. They worked great. I took them off one year...just to see the difference and it was quite remarkable. Put them back on the following year. Close to 3000 lbs total weight. We lost 1/2 knot of speed but well worth the increase in comfort. You could also put the boat onto a beach with no fear of it rolling over if the need came up. I can send you pictures if you're interested.