OK Jeff! ;-)

this is the venerable and rare as hen's teeth Sherpa 'Ops' (assuming it's for 'military operations')... the model came with a few dial variations but I like mine the best, with the raised indices, roulette wheel rotating chapter ring and bright orange accents... and as you can see, it also came in a regular SS version called the 'Ultradive'...

here featured in a 1970 Chronosport catalog, and another from the Enicar catalog...