Answers
Watch Questions, Answered
Direct, numeric answers to the questions people actually ask — no fluff, no marketing. Each links to the relevant watches, comparisons, and our full Key Facts reference.
Water Resistance
What does 200m water resistance mean on a watch?
A 200m (20 ATM) water-resistance rating means a watch is built to withstand the static pressure equivalent of 200 meters and is suitable for recreational scuba diving. The number is a laboratory pressure rating, not a depth you should actually descend to — it describes pressure tolerance, not diving performance.
Accuracy
Quartz vs automatic: which keeps better time?
Quartz keeps far better time than automatic. A good quartz watch drifts roughly ±15–20 seconds per month, while a typical automatic (self-winding mechanical) watch drifts about ±5–20 seconds per day — quartz is one to two orders of magnitude more accurate.
Materials
Is sapphire crystal worth it?
For a watch you wear regularly, sapphire crystal is usually worth it. Sapphire rates about 9 on the Mohs hardness scale (roughly 2,000 Vickers) versus 5–6 for mineral glass, so it resists virtually every scratch you encounter in daily life.
Maintenance
How often should a watch be serviced?
A mechanical watch typically needs a full service — disassembly, cleaning, re-oiling, and regulation — roughly every 5–7 years under common manufacturer guidance. A quartz watch mainly needs a fresh battery every 2–5 years, plus a seal check when the case is opened.
Terminology
What is the difference between a chronometer and a chronograph?
A chronograph is a watch with a built-in stopwatch function (start, stop, reset). A chronometer is any watch certified to a strict accuracy standard such as COSC (−4 to +6 seconds per day). Despite sounding alike, the two terms are unrelated — a watch can be one, both, or neither.
Buying Advice
Is a Seiko 5 a good first automatic watch?
Yes — the Seiko 5 is one of the most widely recommended first automatic watches. It offers a genuine self-winding mechanical movement, day-date function, and (on many models) 100m water resistance at an entry-level price, making it a low-risk way to own a real automatic.
Sizing
What size watch should I get for my wrist?
The best guide is lug-to-lug length, not case diameter: the distance from lug tip to lug tip should not exceed the flat width of your wrist. As a rough starting point, 36–40mm cases suit wrists around 6–7 inches (15–18cm) and 40–44mm suit wrists above about 7.5 inches (19cm).
Movements
Are in-house movements worth it?
It depends on what you value. An in-house (manufacture) movement is designed and built by the brand itself and can offer distinctive engineering, better finishing, and prestige — but reliable third-party calibers such as ETA, Sellita, and Miyota are proven, easy to service, and often the smarter value.
Value
Why are Rolex watches so expensive?
Rolex watches are expensive because of a combination of in-house materials and manufacturing, tightly certified accuracy, and heritage-driven demand that exceeds supply. The company makes its own 904L steel cases, movements, and even gold in-house, and certifies every watch to −2/+2 seconds per day.
How It Works
Do automatic watches need batteries?
No. Automatic (self-winding) watches do not use batteries. They are mechanical: an oscillating rotor inside the watch winds the mainspring from the motion of your wrist, storing energy that drives the movement.