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Scan for outdated or missing drivers - takes under a minuteDriver Scan →Clear out junk files and repair common Windows errorsFree Scan →Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →The Seiko Prospex SPB381, SPB383, and SPB385 are 1968-diver-inspired watches that pair a 60-minute dive bezel with a mechanical GMT hand. All three use the 6R54 movement, whose independently adjustable 24-hour hand makes them caller-style GMTs rather than flyer GMTs with a jumping local hour hand.
The main differences are color and edition: green SPB381 and black SPB383 are the standard models, while the ice-blue SPB385 is a 4,000-piece Save the Ocean limited edition with an extra recycled-polyester strap. Choose among them primarily for the look and the SPB385’s limited-edition package, not for different core specifications.
SPB381, SPB383, and SPB385: what is the difference?
| Reference | Dial and bezel | Edition and included strap |
|---|---|---|
| SPB381 | Green | Standard model |
| SPB383 | Black | Standard model |
| SPB385 | Textured ice blue | Save the Ocean limited edition of 4,000 pieces; includes an additional recycled-polyester strap made with Seichu braiding |
Seiko announced the trio in 2023 as modern reinterpretations of its 1968 diver and introduced the first mechanical GMT movement in a Prospex diver. The SPB385 marks Seiko’s watchmaking 110th anniversary. Seiko says it shares the case and bracelet with the other two references; its distinction is the blue design, limited-edition status, and extra strap. Seiko’s 1968 GMT product page describes the family and its colorways.
How the 6R54 GMT works
The 6R54 lets you adjust the 24-hour GMT hand independently in one-hour increments without interrupting the time-of-day hands, according to Seiko. The GMT hand reads a fixed 24-hour scale on the dial or rehaut, while the unidirectional bezel remains a 60-minute dive bezel.
#1 Best Overall
- STAINLESS STEEL CASE built to endure with style, making this watch your perfect daily companion
- AUTOMATIC MOVEMENT for seamless precision in every tick of this watch
- SCRATCH-RESISTANT CRYSTAL to maintain a pristine look even with daily wear and tear on your watch
- LUMINESCENT HANDS for effortless readability in low-light conditions, ensuring you never miss a moment with this watch
- WATER RESISTANT DESIGN ensuring your watch is ready for any adventure, rain or shine
Caller GMT versus flyer GMT
These are caller-style GMTs: set the independent 24-hour hand to track another time zone while the main hands show local time. A flyer, or traveler, GMT instead lets you jump the local hour hand independently, which is more convenient when you arrive in a new time zone. Hodinkee describes the SPB381’s setup as a caller GMT; the same distinction applies to the shared 6R54 platform.
Specifications
| Specification | SPB381 / SPB383 / SPB385 |
|---|---|
| Movement | Seiko 6R54 automatic mechanical GMT |
| Winding | Automatic |
| Frequency | 21,600 vibrations per hour |
| Jewels | 24 |
| Power reserve | 72 hours, stated by Seiko |
| Case diameter | 42.0 mm |
| Case thickness | 12.9 mm |
| Case length | 48.6 mm, as reported by Fratello; Seiko Boutique UK lists 48.55 mm for SPB381J1 |
| Lug width | 20 mm |
| Crystal | Sapphire with anti-reflective coating |
| Bezel | Unidirectional dive bezel with ceramic insert |
| Water resistance | 200 m diver’s water resistance |
| Magnetic resistance | 4,800 A/m |
| Case and bracelet | Stainless steel with super-hard coating |
| Lume | LumiBrite on hands and indexes |
| Bracelet clasp | Three-fold clasp with push-button release, secure lock, and extender |
Specifications are from Seiko’s 8 March 2023 launch release. Seiko Boutique UK’s current SPB381J1 listing gives regional product details and is subject to change.
Design and fit
Seiko presents the watches as modern interpretations of its 1968 diver. The dive bezel remains the primary tool, with the GMT scale integrated on the dial or rehaut rather than replacing the bezel with a 24-hour scale.
Rank #2
- WATER-RESISTANT: these water-resistant men's dive watches are ISO scuba-approved to depths of 200 meters
- AUTOMATIC: these self-winding, automatic men's watches are powered by your movement, with a power reserve of 41 hours
- STAINLESS STEEL: features a durable 43.8mm stainless steel watch case and bracelet.
- LUMIBRITE DISPLAY: this men's automatic watch features a highly-legible display with LumiBrite hands and markers
- 4R35 CALIBER: equipped with the reliable caliber 4R35 automatic movement, this accurate men's watch keeps precise time
At 42 mm across, 12.9 mm thick, and about 48.6 mm long, the case has a substantial presence. Fratello reviewer Jorg Weppelink described the proportions as wearable and praised the bracelet’s comfort, while identifying the clasp as an area Seiko could improve. These are the reviewer’s subjective impressions; fit depends on wrist shape and personal preference.
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Weppelink preferred the black SPB383 among the standard models and noted the green SPB381’s charm. Hodinkee’s SPB381 reviewer reported excellent legibility and lume, a strong-feeling crown, and a smooth 120-click bezel action that could use a more positive click. Those observations describe the reviewers’ samples, not a guarantee about every watch.
Price and availability
Prices depend on region and date. Seiko’s 2023 launch material listed European recommended prices of £1,400 for the SPB381 and SPB383 and £1,600 for the SPB385. Seiko Boutique UK listed the SPB381J1 at £1,400 when accessed on 7 October 2026; that is a current listing for one reference and region, not proof of current pricing or availability for all three models.
Rank #3
- STAINLESS STEEL CASE built to endure with style, making this watch your perfect daily companion
- AUTOMATIC MOVEMENT for seamless precision in every tick of this watch
- SCRATCH-RESISTANT CRYSTAL to maintain a pristine look even with daily wear and tear on your watch
- LUMINESCENT HANDS for effortless readability in low-light conditions, ensuring you never miss a moment with this watch
- WATER RESISTANT DESIGN ensuring your watch is ready for any adventure, rain or shine
Hodinkee reported a US price of $1,500 for the SPB381 and SPB383 in its hands-on coverage, but that is an article-era figure, not a current quote. The consulted sources do not establish current SPB385 availability or price in every market. Check a local authorized retailer for current stock and pricing.
Which model should you buy?
Choose the SPB381 for green
The SPB381 is the green option in the standard lineup. Choose it if that color is the one you prefer; its core movement and case platform are shared with the other references.
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Choose the SPB383 for black
The SPB383 is the black standard model. Weppelink preferred it in his hands-on comparison, but that is a personal review preference rather than a measurable advantage.
Rank #4
- AUTOMATIC MOVEMENT: Seiko 4R35 automatic movement includes manual winding, 23 jewels, date display, stop-second function, and approximately 41 hours of power reserve.
- 200M DIVER'S WATER RESISTANCE: Rated to 200 meters / 660 feet for diving, with a screw-down crown and screw case back.
- STAINLESS-STEEL CASE: 41.7mm stainless-steel case measures 12.3mm thick with a 49.5mm lug-to-lug distance and 20mm lug width.
- HARDLEX CRYSTAL: Durable Hardlex crystal protects the dial, while LumiBrite on the hands, indexes, and bezel improves low-light visibility.
- DIVER-READY DESIGN: Unidirectional rotating bezel and three-fold clasp with secure lock, push-button release, and extender provide practical functionality.
Choose the SPB385 for ice blue and the limited-edition package
The SPB385 is the choice if you want the textured ice-blue design, numbered limited-edition identity, and extra Seichu-braided recycled-polyester strap. Its core movement, case, and water resistance are shared with the standard models, so its distinction is the design and package rather than different technical performance.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.FAQ
Are the Seiko SPB381, SPB383, and SPB385 traveler GMTs?
No. Their 6R54 movement independently adjusts the 24-hour GMT hand. It does not provide the independently jumping local hour hand associated with a flyer or traveler GMT.
What is the difference between the SPB381, SPB383, and SPB385?
The SPB381 is green, the SPB383 is black, and the SPB385 is an ice-blue Save the Ocean limited edition of 4,000 pieces. The SPB385 also includes an additional recycled-polyester strap; the three share the core movement and case platform.
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- SEIKO WATCH – Seiko SRPL13 Prospex wristwatch.
- COLLECTION – Prospex design.
- CASE DESIGN – Prospex Mare model format.
- MODEL REFERENCE – SRPL13 identifies the specific model.
- WATCH DIAMETER – 41.7 mm.
What is the power reserve of the Seiko 6R54?
Seiko states a 72-hour power reserve for the 6R54 movement.
How much do these watches cost?
Seiko’s 2023 European launch prices were £1,400 for the SPB381 and SPB383 and £1,600 for the SPB385. Seiko Boutique UK listed the SPB381J1 at £1,400 when accessed on 7 October 2026. Prices and availability vary by market and date, and the consulted sources do not verify current pricing for every reference.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
