SEIKO PROSPEX SPB383J1 AUTOMATIC GMT DIVER'S MEN WATCH

Seiko Prospex SPB383J1 — Automatic GMT Diver's Watch

The Seiko Prospex SPB383J1 is a professional automatic GMT diver's watch — a watch that holds two time zones simultaneously while meeting the full Diver's 200M specification. Powered by the 6R54 calibre, the same movement that Seiko uses in the HBC001J1 and HBC002J1 1968 Heritage GMT dive watches and the SPB379J1 Alpinist GMT, the SPB383J1 delivers the 6R54's 72-hour power reserve, hand-winding capability, and +25/-15 seconds per day accuracy in a clean, uncluttered 42mm case. The black ceramic unidirectional bezel and black dial give it a purposeful, tool-watch character, and the 12.9mm slim profile makes it one of the most comfortable-wearing 6R54 GMT dive watches available.

The GMT hand is independently settable for a second time zone — a genuine mechanical complication in a Diver's 200M case at this price point. The sapphire crystal protects the black dial through active use, Lumibrite on the hands and hour markers ensures readability at depth and in low light, and the screw-down crown reinforces the water seal. The silver stainless steel bracelet with hard-coated case completes a specification built for professional use and practical travel.

Key Features

• Seiko 6R54 automatic movement with manual winding — Seiko's current Prospex GMT calibre, first introduced in the 1968 Heritage dive series
• GMT hand — independently settable for a second time zone reference
• 24-hour hand — AM/PM and time zone distinction at a glance
• Approx. 72-hour (3-day) power reserve — reliable performance through a long weekend without wearing
• Accuracy: +25/-15 seconds per day (5°C–35°C) — dependable automatic timekeeping
• Diver's 200M water resistance — built to professional diving standards
• Black dial with baton markers — clean, purposeful tool-watch aesthetic
• Lumibrite on hands and hour markers — superior legibility in low light and underwater conditions
• Black ceramic unidirectional rotating bezel — scratch-resistant, precise, and purpose-built for dive timing
• Sapphire crystal — premium scratch resistance and superior optical clarity
• 42mm stainless steel case with hard coating — professional GMT diver's proportions at 12.9mm slim profile
• Screw-down crown — water integrity protection for diving use
• Date display — everyday practicality built in
• Silver stainless steel bracelet — durable, comfortable, and corrosion-resistant

Why You'll Love It

The SPB383J1 is the Seiko Prospex GMT diver for the traveller who wants a professional dive watch first and a travel watch second — not a travel watch that happens to be water resistant. The 6R54 calibre gives it the same GMT credential as the HBC heritage watches, the Diver's 200M water rating means it can go straight from airport to boat to underwater without a watch change, and the 42mm case at 12.9mm slim makes it the most proportionate and comfortable daily wearer in the Seiko GMT diver lineup. The black ceramic bezel and black dial give it the understated authority of a proper tool watch, and the sapphire crystal keeps it looking new through active daily use. A complete GMT diver at a considered price point for those who use both complications seriously.

SPB383J1 vs SPB381J1 vs HBC001J1 vs HBC002J1 — Which 6R54 GMT Diver Should You Choose?

All four models use the 6R54 mechanical GMT calibre and deliver Diver's 200M water resistance and a 72-hour power reserve. The key differences are in case design, dial colour, and price. The SPB383J1 has a black dial in a clean 42mm case with a ceramic bezel — the most understated and universally wearable of the four, equally suited to diving and daily wear. The SPB381J1 has a green dial in an identical 42mm case — the same specification as the SPB383J1, distinguished only by the more distinctive and ocean-connected dial colour. The HBC001J1 has a rich green dial in the distinctive 1968 Heritage case shape. The HBC002J1 has a classic black dial in the same 1968 Heritage case. The HBC models carry the 1968 design heritage story and the distinctive case shape that comes with it; the SPB381J1 and SPB383J1 are the cleaner, more contemporary GMT divers for those who want the 6R54 specification in a modern case format.

The Seiko Prospex Story

Prospex is a combination of the words "Professional" and "Specifications." Seiko Prospex timepieces are designed to be practical, reliable, and durable — built to meet the high standards required in extreme environments for sports lovers and adventure seekers alike. The story begins in 1881, when Kintaro Hattori founded a clock and watch shop in Ginza, Tokyo — the business that would become the Seiko of today. Since 1965, when Seiko created Japan's first diver's watch, the Prospex dive line has stood for underwater precision and reliability. The SPB383J1 carries that legacy forward in Seiko's most accessible 6R54 mechanical GMT diver.

Backed by Seiko's official warranty. Authentic Seiko Prospex watch, sold by authorised retailer City Chain Singapore.

Also available in the 6R54 GMT Diver family: green dial — SPB381J1, 1968 Heritage green dial — HBC001J1, 1968 Heritage black dial — HBC002J1, and 1968 Heritage white dial — SPB519J1. Explore the full Seiko Prospex Collection or browse all Seiko watches at City Chain Singapore.