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.
Beginner Basics
What's the difference between quartz and mechanical watches?
A quartz watch is electronic: a battery powers a vibrating quartz crystal that a circuit divides down into precise seconds. A mechanical watch is purely mechanical: a wound mainspring drives a gear train and a balance wheel, with no battery or electronics anywhere in it.
Solar & Eco-Drive
How long do solar watches last before the cell dies?
A solar (light-powered) watch's rechargeable cell typically lasts somewhere between 5 and 25 years before it can no longer hold a usable charge, depending on the model, usage, and how consistently it is exposed to light. Most give ample warning first: the second hand starts jumping in two-second steps instead of one when the charge is low.
Buying Advice
Are automatic watches worth it for beginners?
Yes, for the right buyer. An automatic watch is worth it for a beginner who wants to engage with mechanical craftsmanship and accepts the trade-offs — looser accuracy than quartz, needing regular wrist motion or occasional winding, and a service every several years — in exchange for a watch with no battery that can last for generations.
Water Resistance
What does a watch water resistance rating actually mean?
Water-resistance numbers (30M, 50M, 100M, 200M) describe a static laboratory pressure test, not a depth you can safely take the watch to. In practice: 30M means splash resistance only, 50M means brief shallow contact like handwashing, 100M means recreational swimming, and 200M means recreational scuba diving.
Materials
Sapphire vs mineral vs acrylic crystal: what is the real difference?
The three common watch crystal materials trade hardness for toughness in opposite directions: sapphire (about 9 on the Mohs scale) resists nearly all scratches but can chip on a hard impact; mineral glass (5–6 Mohs) scratches more easily but resists shattering better; acrylic (about 2.5 Mohs) scratches the easiest of all but is the most shatter-resistant and can be buffed back to clarity.
Straps
What is a NATO/nylon strap and why do field watches use them?
A NATO (or "nylon") strap is a single continuous length of woven nylon webbing that passes underneath the watch case and through both spring bars, rather than attaching as two separate straps. Field and military watches favor it because if one spring bar breaks, the watch stays looped to your wrist instead of falling off — a real safety feature born out of military use.
Accuracy
How accurate are quartz watches compared to mechanical watches?
Quartz watches are dramatically more accurate: a typical quartz movement drifts around ±15 seconds per month, while even a COSC-certified mechanical chronometer — the industry accuracy standard — is only guaranteed to −4 to +6 seconds per day. That is a gap of one to two orders of magnitude in quartz's favor.
Legibility
What is lume, and why does it glow poorly on some watches?
Lume is a photoluminescent pigment, most commonly Super-LumiNova, painted onto hands and hour markers that absorbs ambient light and slowly re-emits it as a glow in the dark. Cheap watches often glow poorly not because the pigment itself is inferior, but because less of it is applied, applied thinly, or applied only to the hands and not the full set of hour markers.
Sizing
What size watch should I buy?
Choose watch size by 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 rule, 36–40mm cases suit wrists around 6–7 inches (15–18cm), and 40–44mm suits wrists above roughly 7.5 inches (19cm) — but proportion beats any fixed number.
Buying Advice
Hand-wound vs automatic: which mechanical watch should you buy first?
For most first-time mechanical watch buyers, an automatic (self-winding) is the easier and more practical choice, since it winds itself from ordinary wrist motion. A hand-wound watch is the better pick specifically for someone who wants the daily winding ritual, or the thinner case that hand-wound movements often allow by omitting the rotor.
Terminology
What is a day-date complication on a watch?
A day-date complication is a feature that displays both the current day of the week (spelled out or abbreviated) and the calendar date, typically through small windows near the 3 o'clock position, or sometimes as a single combined window. It is one of the most widely used complications because it adds genuine daily utility without much added bulk or cost.
Maintenance
Why do watch batteries die every 2-3 years, and which watches never need one?
A standard quartz watch battery dies because it continuously discharges to power the oscillating crystal circuit and the stepper motor that moves the hands, typically lasting 2–5 years depending on the movement and how many functions (chronograph, alarms) it drives. Two watch types never need a battery at all: solar-powered quartz (Citizen Eco-Drive, Casio/Seiko Tough Solar), which recharges from light, and mechanical automatics, which run on a wound mainspring instead of electricity.
Solar & Eco-Drive
What is the best solar watch under $200?
The best solar watch under $200 is the Casio MTP-S120L, a solar-powered quartz field watch with 100m water resistance that goes 5–25 years between battery services — light on your wrist keeps its rechargeable cell topped up, so there is no routine battery swap.
Sizing & Fit
What is the best automatic watch for small wrists?
The best automatic watch for small wrists is the Tissot PRX Powermatic 80 in its 35mm case size — a genuine Swiss automatic with an 80-hour power reserve, sized for the 6–7 inch wrists that most modern automatics overhang.
Dive Watches
What is the best dive watch for daily wear?
The best dive watch for daily wear is the Citizen Promaster Sea Eco-Drive Diver — an ISO 6425-certified 200m diver whose solar Eco-Drive movement never needs winding and goes 5–25 years before its rechargeable cell needs replacing, making it the true grab-and-go choice.
Nickname decoder
What watch is the "Casio Royale"?
The "Casio Royale" is the community nickname for the Casio AE1200 World Time, reference AE1200WH-1A: a 42.1 mm resin digital running Casio module 3299, with a world-map LCD, 48-city world time, 100 m (10 ATM) water resistance and a battery Casio rates at ten years. It sits in the under-$50 band on Amazon.
Nickname decoder
What watch is the "CasiOak"?
The "CasiOak" is the nickname for Casio's G-Shock GA-2100 line, whose octagonal case echoes the Audemars Piguet Royal Oak. The version in this catalogue is the GA-B2100-1A: a 45.4 mm Carbon Core Guard resin case, 48.5 mm lug to lug and 11.9 mm thick, module 5689 with Tough Solar and Bluetooth, 200 m (20 ATM) water resistance, in the low-hundreds band.
Nickname decoder
What watch is the Seiko "Turtle"?
The Seiko "Turtle" is the nickname for the Prospex cushion-case diver line, represented in this catalogue by the SRPE05: a 45 mm stainless steel case, Seiko's in-house automatic caliber 4R36 with day and date, sapphire crystal, a unidirectional bezel and an ISO-certified 200 m (20 ATM) dive rating. It sits in the mid-hundreds band.
Nickname decoder
What watch is the Seiko "Samurai"?
The Seiko "Samurai" is the nickname for the Prospex diver with the sharp, angular case, represented in this catalogue by the SRPL13 (and the SRPF03): a 41.7 mm stainless steel case, Seiko's in-house automatic caliber 4R35 with date, Hardlex crystal and a 200 m (20 ATM) dive rating. It sits in the mid-hundreds band.