What do the Canadian police do in the summer when a drunken idiot is terrorizing the populace by riding his jet ski like an ass? "Whelp, out on the water, nuthin' we can do, eh?" I imagine it's like the U. S., where any number of law enforcement agencies have jurisdiction to write tickets and arrest folks. And though IANAL, I don't imagine the physical state of the lake water going from liquid to solid being a factor.