SEIKO 5 SPORTS SRPD79K1 AUTOMATIC STEALTH BLACK MEN WATCH

How does an automatic watch work — does it need charging?

Neither charging nor a battery. A weighted rotor inside the movement swings as your wrist moves and winds the mainspring, and the mainspring drives the watch. A normal day of wear keeps it going. It does need enough winding to run, though — a quiet day at a desk may not supply it, in which case wind it by hand through the crown rather than waiting for the watch to catch up.

What happens if I leave it off for a few days?

It stops, and that is normal rather than a fault. Calibre 4R36 holds roughly 41 hours from a full wind, so a watch taken off on Friday evening will usually have stopped before the weekend is out. Wind it by hand, reset the time, day and date, and it carries on. On accuracy, Seiko rates this movement at −35 to +45 seconds a day as a factory setting, and notes that real-world figures depend on how long you wear it, how much your arm moves, temperature and how fully it is wound — so expect to correct it from time to time.

What is the rotating bezel for?

Measuring how long something has taken. Turn the bezel until its zero marker sits under the minute hand, and from that moment the minute hand reads the elapsed minutes straight off the bezel. Seiko specifies it as one-way, which is a deliberate safety measure: a knock can only ever rotate it so the elapsed time reads longer than it truly is, never shorter.

Is this a diver's watch?

No. The case and bezel draw on Seiko's sports watch heritage, but Seiko specifies this one as enhanced everyday water resistance at 10 bar, without a diver's designation. In practice that covers rain, hand-washing, showering, swimming and snorkelling. It does not cover scuba diving, and the 100-metre figure is a pressure rating rather than a depth you can take the watch to. One habit worth keeping: the crown pulls out rather than screwing down, so never pull or turn it while the watch is wet, and rinse the watch in fresh water after the sea or a chlorinated pool.

How do I set the day and date?

Both are set from the crown's intermediate position, with the watch still running. The important restriction is the timing: Seiko's instructions for the 4R36 state that you must not set the date or the day between 9:00 pm and 4:00 am, and that amending them during those hours may cause problems such as the date or day failing to change the next day, or may cause damage. Move the hands away from that window first, set the day and date, then set the time.

How does 42.5mm wear, and can the strap be adjusted?

The figure to judge it by is the 46mm lug-to-lug, which is the span actually reaching across your wrist, and it is short relative to a 42.5mm diameter. At 13.4mm deep and 94g the watch has real presence on the wrist rather than disappearing. Nylon adjusts at the buckle, so there is nothing to size or remove; strap adjustment is available in store with your warranty book if you need help with it.

What does the warranty cover?

Buying the SRPD79K1 from City Chain Singapore, an authorised Seiko retailer, includes a 3-year warranty against manufacturing defects. It does not extend to accidental damage or ordinary wear, and routine servicing is separate from warranty work. Keep your warranty card and proof of purchase, as the watch cannot be submitted for warranty service without them.