"As designated by the commissioner" means those places where the Commissioner of Safety has explicitly excluded ski craft (aka PWCs) from operating. Through regulations, the Commisisoner has excluded ski craft in Winnipesaukee in four coves: Blackey's Cove, Salmon Meadow Cove, Greens Basin, and an area south of Jerry Point on Bear Island. All are designated as such on Bizer's chart.
I just found the online regulations at
http://www.state.nh.us/safety/ss/bodies.html It mentions a place called Cedar Cove, but that's a new one on me. I've never heard of Cedar Cove. Has anyone else.