About this time years ago, a kayaker died in the Chespapeake Bay not to far from Annapolis. Partial wet suit, life jacket, etc. He was overcome by short waves and cold water on his head, legs, etc. He was only a mile or so offshore. No one saw him in time.
Fifty-ish degree water doesn't take long to do you in if you aren't really used to dealing with it. Even 'frogmen' (seals or navy divers) have to watch it -- and they are trained to eal with cold water. For most us, even good swimmers it really is killer. Add getting doched by a wave every 3-5 seconds and you won't be breathing too long.
Sad situation.