I have a Jack Browne mask in my "historic" stash. One of the Navy Master Divers I worked with called it "the Black Death". Keep in mind that this was the early 1970s when the KMB-8s (Kirby Morgan Band Mask version 8) were the lastest and greatest.
Jack Brownes were pretty long in the tooth by then. You have to remember that the only alternative when it was introduced was full deep sea gear.
Jack Brownes were pretty long in the tooth by then. You have to remember that the only alternative when it was introduced was full deep sea gear.