Bill, I couldn't agree more with your notion that sea kayakers should think and express themselves as mariners do: velocities in knots, distances in nautical (sea) miles. With our physical closeness to the water, wind, weather, currents, tides, if anyone ought to think of themselves as mariners, it is the sea kayaking community.
Osprey, I like your idea on reporting wave height. And in the absence of measured speeds and heights, let's just report what we see. David Burch's "scattered popcorn" for approx. 10 knots of wind, "popcorn everywhere" for 20 knots, and "conspicuous spray....and streaks of foam" for 30 knots, seems to work pretty well as a kayaker's version of the Beaufort Scale.