A 300m dive watch on a 5m-rated strap is a 5m system. Here is what ISOfrane®, Tropic® and NATO straps actually do differently underwater — and when each one is the right call.

The number stamped on a dive watch is laboratory pressure, not depth — and the industry convention sits at a specific safety ratio. Here is what 100m, 200m, 300m, and 500m actually cover underwater.

Not every "dive watch" is actually built for diving. The difference comes down to two ISO standards — 22810 and 6425 — and what each one really guarantees underwater.