My dad had a Merchant Marine ID card from about 1941, 1942 or 1943. I can't find, and want to know why he had it.

He was in the Army Air corps,in WW2, China-Burma-India theater. He spent more the 2 years in China, with the 8th Airdrome Squadron. He went over seas in 1943, came back 1/1946.

What can I do to learn why he had this picture ID, it was a large ID card with black on white and a photo.

Also I know he shipped out on the SS James Hoban, and returned on the USS Gen'l JR Brooke.

Any info on these would be appreciated too.

Thank You All,Howard.