One of the reference databases SLPL subscribes to is Fold3.com. Fold3.com concentrates on military records (although it also provides access to various non-military records).
Fold3.com also provides access to photographs of World War II and the Vietnam War. One of its photo sets is the Vietnam War—Navy Photos. This photo set includes official photos of U.S. Navy equipment and weapons, plus Navy personnel engaged in various wartime activities. Subcategories include (to name a few):
Some photos are in color, while others are black & white. Individuals in photos are sometimes identified, but often not. Most photos are accompanied by an information card that generally provides:
Navy official photo number
Date and place photo was taken
Brief description of scene depicted
Name of photographer
A Basic Search by name of individual may turn up photos of interest. You can also search for these photos in Advanced Search by doing a keyword search. For example:
patrol boats—1,386 hits (88 after filtering for Vietnam War-Navy Photos category)
seals—3,685 hits (33 after filtering for Vietnam War-Navy Photos category)
Some good news for you: holders of a valid SLPL library card can search this database from home! Go here to get started.