This photographic cancel of the USS Nevada was mailed to Mr. Crosby’s PO box on Aug 11 1931.
The cancel is in red ink.
The Crosby-Beazell cachet covers were unique because of the high quality of the ship photo on the cover. This was achieved by using photographic paper to make the envelope. Beazell was a photographer and Crosby collaborated with him to develop the ship photos onto the paper, which afterwards they converted into an envelope. Then Crosby arranged for the envelope to be cancelled aboard the corresponding ship.