The Submariner you see here is reference 5514, which was a model made specifically for COMEX. It differed from the consumer reference 5513 in that it had a helium escape valve on the left side of the case, similar to the beefier Sea Dweller. Only around 150 reference 5514s were made, this is one of them.
What makes this already extremely rare diving watch even more valuable is that it also bears military markings of the Argentine NAVY. The "A.R.A." on the dial stands for "Armada de la República Argentina." The caseback is engraved with both a COMEX number and a military issue number
HODINKEE