The only instance I know of an attempt to install a venturi drain in a conventional kayak was a failure. Water just kept coming in, no matter the speed generated by the very fast paddler. They do work for skis, albeit often quite slowly, but almost certainly because there is always a bit of vertical distance between the footwell and the bottom of the hull. I've also never seen one of the little teardrop thingies in the picture Reg posted. Maybe that's the key to making it work on a single-layer hull. Dunno.

I have a vague memory, possibly/probably quite faulty, that some marathon canoes used some kind of auto drain system. Never seen it though. Perhaps if you can find some canoe racers they would have more info, or maybe a company like Wenonah would be a source.