Underneath my coat I'm wearing my old Beretta shooting vest. Hard to see. Alas I boiled it washing it when the machine got stuck with hot water on. The suede edges shrunk badly. I'll need to take some pictures. It's design might form a tailored basis for a new one, Different and more pockets.

My Pro Cam Fis coat actually unzips the sleeves and turns into a "vest". But way too heavy and too warm for warm climes. A good non waterproof safari coat though. It has a huge number of pockets. Maybe 19 to 21.