Very unique. See old navy films from WWII to see in use. They are supposed to be black, but were dyed imperfectly as was typical for WWII web gear.
World War 2-10 pocket ammunition belt, new old stock. Original issue heavy cotton canvas. Khaki has been over-dyed navy blue by the navy department for wear with navy uniform. These ammo belts have lots of shelf-wear on these. Only a few to offer. The blue navy garand ammo belts are probably what were used by Navy Raiders.