I think I remember those on Barnegat bay (very shallow water in most places) but what I remember most were the Garvey races. I was a lifeguard - Island Beach State Park circa 1979
Midwestern boats made for shallow lakes. Currently by Melges here in Wisconsin. There are a number of fleets nearby of MC, C, E, and A scows. There's an MC in our sailing club. Huge amount of sail area on a little, flat, cat rigged boat. They really fly.
But the local one deign fleets of even the small scows still seem to me much as Christian describes.