I have this automatic watch since 1977 and still working like a brand new: Seiko Diver 6105-8110, a vintage.

Seiko 6105s were very popular with American GIs in Vietnam, as the watch had a reputation for ruggedness and durability in the harsh Vietnamese combat environment.

Scubawatch trivia:
Capt. Willard, played by actor Martin Sheen in the movie Apocalypse Now, wore a Seiko 6105 dive watch.