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One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchSeiko introduced the Prospex Sumo Solar GMT SFK001 and SFK003 in 2023. They share the same solar-powered dive-watch platform and technical specifications; the clearest reported difference is the dial color: blue on the SFK001 and green on the SFK003. Both have a local-jumping GMT hand, a 45 mm case and 200 m water resistance.
What are the Seiko SFK001 and SFK003?
These are Prospex Sumo Solar GMT dive watches, not mechanical Seiko 5 Sports GMTs. Launch coverage described them as Sumo-based designs with Seiko’s solar quartz Caliber 5K65 and a flyer-style GMT function. Hodinkee’s February 15, 2023 launch coverage reported spring 2023 retailer availability.
Seiko Philippines lists the J1 versions as the Prospex SFK001J1 and SFK003J1 Sumo Solar GMT. Seiko Philippines Official Store product pages provide the specifications below; regional reference suffixes and availability can differ.
SFK001 vs. SFK003: what is different?
| Reference | Dial color reported at launch | Shared platform |
|---|---|---|
| SFK001 | Blue | Solar Caliber 5K65; Sumo dive-watch case and specifications |
| SFK003 | Green | Solar Caliber 5K65; Sumo dive-watch case and specifications |
The colorways are the clearest model distinction in the launch coverage. Choose between them mainly by dial preference, while checking the exact regional reference and seller listing before buying.
#1 Best Overall
- SEIKO WATCH – Seiko SFK001 wristwatch with a GMT hand function.
- DIAL DESIGN – Blue dial provides the watch face design.
- CRYSTAL – Sapphire crystal construction.
- BEZEL – Unidirectional rotating bezel design.
- WATCH DIAMETER – 45 mm.
How does the 5K65 GMT function work?
The 5K65 is a solar quartz movement, not an automatic mechanical caliber. Its 24-hour hand tracks a second time zone, while the local hour can be adjusted in one-hour jumps without stopping that 24-hour indication. That is useful when changing time zones: adjust local time while preserving the reference time shown by the GMT hand.
Seiko’s official listing also specifies a date display, calendar-linked time-difference adjustment, quick-start and overcharge prevention, with an accuracy rating of ±15 seconds per month. That rating is the manufacturer-listed specification, not a guarantee of identical real-world performance for every watch.
Rank #2
- PADI SPECIAL EDITION: Men's Prospex Sea diver featuring a PADI Special Edition design with a stainless-steel case and ceramic bezel display.
- AUTOMATIC MOVEMENT: Seiko 4R36 automatic movement offers manual winding, 24 jewels, day/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.
- SAPPHIRE CRYSTAL: Sapphire crystal with magnifier and inner anti-reflective coating provides durable dial protection and improved readability.
- DIVER-READY FEATURES: 45mm stainless-steel case, unidirectional rotating bezel, LumiBrite hands, indexes and bezel, plus a secure three-fold clasp with extender.
Case size and dive-watch specifications
| Specification | Listed value |
|---|---|
| Case material | Stainless steel |
| Diameter | 45 mm |
| Thickness | 13.2 mm |
| Lug-to-lug | 51.8 mm |
| Lug distance | 20 mm |
| Crystal | Sapphire with inner anti-reflective coating |
| Water resistance | 200 m / 660 ft |
| Bezel and crown | Unidirectional rotating bezel; screw-down crown |
| Luminescence | LumiBrite on hands, indices and bezel |
The 45 mm diameter and 51.8 mm lug-to-lug measurement are especially important fit checks; the watch may wear large, depending on wrist shape and preference. The 20 mm lug distance identifies strap width, but by itself does not establish compatibility with a particular replacement bracelet or end link.
Price and availability depend on market and date
Hodinkee reported a launch-era retail price of $775 for either colorway in 2023. This is a historical US price, not confirmation of today’s price or global availability. Seiko Philippines listed each J1 reference at ₱45,040 and marked both sold out when its pages were crawled in 2026. That listing describes the Philippine store’s status, not stock in other markets. Current seller inventory, warranty coverage and pricing should be verified for the specific region and reference before purchase.
Rank #3
- STUNNING BLUE DIAL: this rugged sports watch features a beautiful Manta Ray-patterned blue dial, with Lumibrite dial indicator hands and markers for low light and a magnified day/date calendar
- BLACK BEZEL: this versatile men’s watch features a black ceramic unidirectional bezel with distinctive scalloped edging, for elapsed timing
- AUTOMATIC & MANUAL: SRPF77 automatic watches for men power up with your natural movements, and feature the ability to wind manually, with 41 hours of reserve power
- WATER-RESISTANT: these rugged stainless steel dive watches for men feature a deep blue silicone strap and are both stylish and robust, following ISO standards for scuba, and are water-resistant to 200 meters
- 4R36 CALIBER: equipped with the reliable 4R36 caliber, these precise men’s wrist watches ensure the most accurate timekeeping
Do not confuse the SFK Sumo GMTs with the SSK GMTs
The SFK001 and SFK003 are Prospex Sumo solar dive GMTs. The SSK001 and SSK003 belong to the separate Seiko 5 Sports GMT line covered in Seiko Watch Corporation’s June 8, 2022 official SSK press release. Similar reference numbers do not make these the same watch family: check the full prefix, collection and movement type in a listing.
Quick Recap
Best Value
- 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
Rank #4
- 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
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.
