Coldest water I ever encountered was at Lake Lewis (Fort Lewis) my freshman year in college. Plunged into the lake from a rope drop at 40 feet, water was less than 50 degrees. My body was not prepared for the shock. Had to be fished out by the lifeguard.
Had no problems after that, once I knew what to expect.
Playing the Palomino Club in North Hollywood in ‘79, swapping shows with Ricky Nelson. Crazy Texan singer wanted to surf, which neither of us had ever done. Found a board rental on the beach, they asked if we had dry suits, nope. They said water is 52 degrees. We said fine. I got hypothermia. Still occasionally get violent shivers if hit with cold wind suddenly.
We used to waterski at American Lake (Ft Lewis) Wa. year round, rain or shine. Yes to wet suits and dry suits.