You see "200m" printed on a watch and think: so I can dive to 200 metres. You can't. The number does not mean that, and the mistake is how a lot of watches end up flooded.
Here is what the rating actually tells you, which features matter more than the number, and how it plays out on a real watch, the OLTO-8 TIDE X.
What 200m on a watch means
A water resistance rating is a pressure rating. In a lab, the watch is tested at a pressure equal to what the stated depth would produce on a motionless object. Standards such as ISO 22810 describe how this kind of test works. So "200m" means the case passed a test at that pressure. It is not a promise about how deep you can go.
Why you can't treat it as a depth limit
Water pressure on a watch in the real world is higher than the lab figure for the same depth, because you are moving. A hand slapping the surface, a dive off a boat or a wave hitting your wrist all add pressure for a moment. Gaskets also age, and heat and soap make them age faster. So the rating is a safety margin, and it works best as a guide to the kind of water you can take the watch into.
The features that matter more than the number
- A screw-down crown. The crown screws into the case and seals it. If you forget to screw it down, the rating means nothing.
- A screw-down case back. It closes the other main opening in the case.
- A solid case and a sapphire crystal. They are the parts that have to survive the pressure.
The OLTO-8 TIDE X on paper
The TIDE X is rated to 200 metres. It has a screw-down crown and a hexagonal screw-down case back. The case is three-piece 316L stainless steel with a sandblasted finish, and the top crystal is sapphire with an anti-reflective coating. The back glass is K1 mineral glass. The listing positions it for casual diving, snorkelling and water sports.
The design idea is an underwater mechanical city: a skeleton dial lets you see the movement working, and the counter-clockwise bezel has an anodised aluminium insert. The movement is the self-developed SL2204B automatic, 28,800 vibrations per hour, 24 jewels and a 42-hour power reserve. The strap is silicone, which suits wet use.
| Specification | OLTO-8 TIDE X |
|---|---|
| Water resistance | 200 m |
| Movement | SL2204B automatic, 28,800 vph, 24 jewels |
| Power reserve | 42 hours |
| Case | 316L stainless steel, three-piece, sandblasted |
| Crystal | Sapphire with anti-reflective coating (front), K1 mineral (back) |
| Crown and case back | Screw-down crown, hexagonal screw-down case back |
| Bezel | Counter-clockwise, anodised aluminium insert |
| Strap | Silicone with stainless steel buckle |
Looking after a water-resistant watch
- Screw the crown down fully before the watch goes near water.
- Never press the crown or buttons underwater.
- Keep it out of hot showers, saunas and steam. Heat softens gaskets.
- Rinse it with fresh water after the sea and let it dry.
- Have the gaskets checked from time to time by a watchmaker.
Where to find it
The TIDE X is in Ocean Blue, Rust Red and Neon Green. See the full OLTO-8 collection, or browse mechanical watches under $500. Malichus is an authorized OLTO-8 dealer, and you can verify our authorization.
Quick answers
Is 200m water resistance the same as a 200 metre dive depth?
No. It is a pressure rating from a lab test, so treat it as a margin of safety.
Can I wear the OLTO-8 TIDE X in the sea?
The listing positions it for casual diving, snorkelling and water sports. Keep the crown screwed down and rinse the watch afterwards.
What is a skeleton dial?
A dial with openings that let you see the movement working inside the watch.
How long does the TIDE X run when it is not worn?
The movement has a 42-hour power reserve, so it will stop after a little under two days.
