F4U-1 Corsair of VF-17 landing on the flight deck of USS Bunker Hill CV-19, 1943.
The white bar adition to the blue circle/white star entered service on the 29th June of 1943. The red bordered version seen here lasted only a short period and was quickly substituted by the final blue bordered version (from August 14 onwards). I think what we are seeing here is either 2 planes of the same unit using different ensigne probably because they were photographed during a transitional period when the new ensignes were being applied or the same plane photographed before and after receiving the new markings. This probably dates this photo to the early summer of 1943 (July or August).
A great plane, nice shot. Victor Sierra