ISO 6425:2018, Horology — Divers' watches, states in its published scope that it "specifies requirements and test methods for divers' watches and for saturation divers' watches for use in deep diving".
The scope defines what the standard applies to, verbatim: "It applies to divers' watches designed to withstand diving in water at depths of at least 100 m and equipped with a secured measuring system to indicate the diving time, which is visible in darkness." It adds that it "indicates the marking which the manufacturer is authorized to apply to them".
So a rotating bezel, a rubber strap or a depth marking do not by themselves make a watch a divers' watch in the standard's terms. The standard is separate from ISO 22810, which covers ordinary water-resistant watches.
Edition 4, published October 2018, confirmed as an International Standard in 2024.
Sources
Every statement above traces to one of these. Read on the date shown.
- Tier 1 ISO 6425:2018, Horology — Divers' watches, edition 4, published October 2018, confirmed 2024, source read 2026-09-26