My pop got a speeding ticket there back in '77 or '78, my brother was on a ski, and when he let go, he went into the NWZ, just inside the bouys, as there was a bunch of boat traffic behind him. Dunno how much that was, but it started our "going to the river" days, Havasu, Parker, and Mohave. (1961 c/20 chevy p/u w/6cyl, cab over camper, and 1974 18' eliminator, the good ol' days).
FWIW, hull numbers have to be a contrasting color, (thats open to opinion

) and 3"
Daniel