I have an idea:
Lets all Agree to elchase's idea and then if the tests show that 15, 16 or 18 MPH or whatever is the average minimum plaining speed then we go for it, make it law...
...then we cruise by his house on the lake as many times as we possibly can at night, abiding by the law of course. Then we see what, if any, shoreline, boat, swim raft, dock, etc. is left standing in the morning.
To quote elchase directly:
"Hint: Be careful what you wish for.

"