Bogarts Cap in The African Queen

[Andy Hudson]

Does anyone know what type of cap Bogart is wearing in The African Queen? It has the look of a skipper, but the fit is tight to his head like a WWII A3 cap, and it has the black leather brim like a skipper, but with more of a vintage baseball brim shape. I’ve never seen anything quite like it anywhere, and I’ve come up empty with multiple internet searches.