Dry suit question

I know of one local paddler
who wears a drysuit locally when paddling solo during the winter (for an extra margin of safety in the event of a capsize-she doesn’t have a roll). I generally just wear mysterioso gear as a base layer under my farmer jane. My instructor last week at MBK had on a dry suit. We were in the water over 3 hours, and I think the surface temp was stated to be 52 degrees. I had on my mysterioso fleece and a 3mm farmer jane wetsuit, and I was quite chilled by the end of the class. Of course, we were in and out of the water, and also standing on the shore for short periods of time. Local surfers switch to 4mm full wetsuits and booties during the cooler months,or at least the ones I know do.