ISO 6425 is the international standard for dive watches. It specifies minimum requirements for water resistance, legibility in darkness, magnetic and shock resistance, and a unidirectional bezel with elapsed-time markings. A watch can only be marketed as a 'diver's watch' if it meets the standard.

Do I need 300 m of water resistance for recreational diving?

No. Recreational scuba diving rarely exceeds 40 m of depth. Any ISO 6425-certified watch with a 200 m or higher rating is more than sufficient. Higher ratings (500 m, 1000 m) matter only for saturation diving and commercial applications.

What does a helium escape valve actually do?

It releases helium that has accumulated inside the watch case during saturation diving (where divers live in pressurised habitats for days). For recreational and even most professional diving it is not relevant.

Best Watch Lists

Best Dive Watches - Editorial Picks

A focused list of dive watches whose specifications, history, and ownership economics make them defensible choices for both serious divers and on-the-wrist daily wear.

By Ira Zoot

Reviewed against editorial standards 1 cited source Last updated April 26, 2026 Subject-matter reviewed

Rolex Submariner

The reference dive watch. ISO 6425-compliant, 300 m water resistance, in-house 3230/3235 movements. Long waitlists at retail, strong resale.

Omega Seamaster Professional 300M

Master Chronometer–certified, 300 m rated, with helium-escape valve and laser-engraved wave dial. Better value at retail than the Submariner and broadly available.

Tudor Pelagos

Titanium case, 500 m rating, in-house MT5612 movement. The most over-built sub-€5K luxury dive watch on the market.

Blancpain Fifty Fathoms

The first modern dive watch (1953), pre-dating the Submariner by a few months. Larger and more dressy than its peers, with haute-horlogerie finishing.

Seiko Prospex

Japanese alternative offering ISO 6425 ratings at a fraction of Swiss prices. The SPB143 'modern 62MAS' has become a default first serious dive watch.