From a personal perspective, it all depends what you mean by snorkelling and drysuits.
As an ancient lifelong snorkeller, never a scuba diver, I do remember the days in the mid twentieth century when a drysuit was a genuine option for snorkellers, or "skin divers" as they would have been known back then. The difference was that the dry suits in the 1950s and early 1960s were light, usually two-piece garments, without bulky valves, worn with fabric thermal undersuits. Learning how to don, vent and seal the suit was a must right from the start.
After undergoing surgery almost twenty years ago, I decided to do a little snorkelling in the cold waters of the North Sea off the coast of North East England. My exposure suit of choice was at first the close-fitting safety-yellow vintage So-Lo Marx Skooba-"totes" drysuit you see above from the historical diving equipment collection I amassed over the decades. This suit kept me perfectly warm and dry while snorkelling on the surface and taking the occasional shallow dive after opening the wrist or face seals to vent it. To keep this irreplaceable historical suit in reasonable condition, I later purchased a new
Hydroglove replica vintage drysuit, which turned out to be equally serviceable against the elements while snorkelling, based as it was on the original Skooba-"totes" design.
In recent years, I read a report somewhere about dry-suited snorkellers swimming with seals off the Farne Islands, many miles further up the coast from where I live. These snorkellers, who used modern-style bulky loose-fitting drysuits to keep warm and dry, spent all or most of their time floating and swimming on the surface while they were in the company of these marine mammals.
