Is the Type E watch suitable for diving ?
The Type E collection was designed for versatile daily wear: at the office, in the evening, at automotive events. Here is a clear picture of what it handles without concern, and where its range stops.
What it handles without concern
With 5 ATM water resistance, the AJ-003 covers the everyday situations most wearers will encounter: rain, washing up, perspiration, a day at the beach without swimming. It also handles occasional pool swimming or a boat trip without prolonged immersion. Our guide to beach use spells out exactly what stays reasonable.
What it doesn't do: diving
Scuba diving, freediving, or any use involving significant pressure variations go beyond what the AJ-003 was designed for. This isn't a matter of degree; it's a difference in design.
A watch certified for diving under ISO 6425 combines features the AJ-003 doesn't have: a lockable screw-down crown, a unidirectional rotating bezel graduated for dive timing, a water resistance indicator, and sometimes a helium escape valve for saturation diving. These are technical elements designed specifically for prolonged immersion and safety at depth, not interchangeable aesthetic options.
A design built for a different purpose
The semi-integrated crown, domed sapphire crystal, and polished fixed bezel of the AJ-003 reflect a different aesthetic and practical logic from a diving watch. That distance from diving standards takes nothing away from the quality of the watch itself: it simply confirms that it was designed for a different context. The same logic applies in reverse : a watch designed for daily wear was not built for the depths.
It's also worth knowing that a watch's water resistance can decrease slightly over the years as the internal gaskets age, even without any particular incident. That's one more reason to have this checked during a movement service.
The right tool for the right use
If diving is part of your regular activities, owning a watch specifically certified for it alongside your AJ-003 is the most sensible approach. You keep the AJ-003 in the context where it excels every day, dressed-up occasions, automotive outings, while a purpose-built instrument handles the water.
If diving is only occasional, some owners prefer to remove the AJ-003 rather than rely on the margin offered by 5 ATM. It's a personal choice, but the more cautious approach given the gap between 5 ATM and the standards actually designed for immersion.
In summary
The 5 ATM water resistance of your Type E watch covers everyday use comfortably, including occasional swimming. Diving, however, requires a fundamentally different design that the AJ-003 was never intended to provide. For case care after light nautical use, our cleaning guide remains the best reference to follow.