In 1943, Jacques Cousteau and Émile Gagnan patented the Aqua-Lung — the first open-circuit #SCUBA system. Since then, an estimated 9 million certified #divers worldwide have descended beneath the surface, unlocking an entirely new frontier of human exploration. The original #divecomputer wasn’t digital. It was mechanical. A watch built to measure the one variable you couldn’t afford to lose. That lineage runs straight through the tool watches of today. Marathon’s #SAR line was engineered for military and professional divers, built to international dive standards, pressure-tested, and legible at depth. Long before screens and sensors, there was steel, lume, and a bezel. #purposebuilt