Updated
Omega Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) vs Seiko 5 Sports GMT SSK001
Omega's chronograph meets Seiko's GMT watch
Quick Verdict
The Seiko 5 Sports GMT SSK001 ($250–$500) delivers Seiko In-House Automatic GMT technology in the tier below the Omega Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) ($10,000–$25,000). The 5 Sports GMT SSK001 measures 42.5mm and is rated 100m (10 ATM). The Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) justifies its premium with Swiss Made heritage and Omega Co-Axial Master Chronometer calibre 8912, automatic, METAS certified, time zone function. Both represent excellent choices in the luxury watch category.
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Omega
Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial)
$10,000–$25,000
Specifications Compared
| Feature | Omega Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) | Seiko 5 Sports GMT SSK001 |
|---|---|---|
| Price | $10,000–$25,000 | $250–$500 |
| Case Size | 55 x 48mm, 18.26mm thick, 48mm lug to lug | 42.5mm |
| Movement | Omega Co-Axial Master Chronometer calibre 8912, automatic, METAS certified, time zone function | Automatic Caliber 4R34 (True GMT) |
| Caliber Type | Omega 8912, Master Chronometer | Seiko In-House Automatic GMT |
| Power Reserve | About 60 hours | 41 Hours |
| Water Resistance | 1200m (120 bar) | 100m (10 ATM) |
| Crystal | Flat sapphire, anti-reflective both sides | Hardlex Crystal |
| Case Material | Grade 5 titanium with 18k Sedna gold bezel-lock pusher and crown, bidirectional polished blue bezel with Ceragold numerals, helium escape valve, screw-in crown | Stainless Steel |
| Origin | Swiss Made | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Omega's design language vs Seiko's approach
The Omega Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) features a Grade 5 titanium with 18k Sedna gold bezel-lock pusher and crown, bidirectional polished blue bezel with Ceragold numerals, helium escape valve, screw-in crown case at 55 x 48mm, 18.26mm thick, 48mm lug to lug with Flat sapphire, anti-reflective both sides protection. The Seiko 5 Sports GMT SSK001 offers Stainless Steel construction at 42.5mm with Hardlex Crystal. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Omega Co-Axial Master Chronometer calibre 8912, automatic, METAS certified, time zone function vs Automatic Caliber 4R34 (True GMT)
The Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) runs the Omega Co-Axial Master Chronometer calibre 8912, automatic, METAS certified, time zone function (Omega 8912, Master Chronometer, About 60 hours power reserve) at standard frequency. The 5 Sports GMT SSK001 uses the Automatic Caliber 4R34 (True GMT) (Seiko In-House Automatic GMT, 41 Hours reserve) at 21,600 vph (3 Hz). The Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) edges ahead on power reserve.
Wearability & Fit
55 x 48mm, 18.26mm thick, 48mm lug to lug vs 42.5mm — different wrist presence
At 55 x 48mm, 18.26mm thick, 48mm lug to lug, the Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) has a bolder wrist presence compared to the 5 Sports GMT SSK001 at 42.5mm. Water resistance differs: 1200m (120 bar) vs 100m (10 ATM).
Value & Cost of Ownership
Seiko sits in the lower tier
The Omega Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) sits at $10,000–$25,000 and the Seiko 5 Sports GMT SSK001 at $250–$500. On the specs that outlast any price: the Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) uses Flat sapphire, anti-reflective both sides with About 60 hours, against Hardlex Crystal and 41 Hours on the 5 Sports GMT SSK001. Service intervals are typically 5-7 years for both.
Water Resistance
1200m (120 bar) vs 100m (10 ATM)
The Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) is rated to 1200m (120 bar) while the 5 Sports GMT SSK001 handles 100m (10 ATM). The Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) is better suited for water activities.
Our Verdict
Omega
Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial)
Choose the Omega Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) if you prioritize Omega 8912, Master Chronometer engineering, Swiss Made craftsmanship, and 1200m (120 bar) water resistance. At $10,000–$25,000, it delivers Omega Co-Axial Master Chronometer calibre 8912, automatic, METAS certified, time zone function with About 60 hours power reserve.
Check Price on AmazonSeiko
5 Sports GMT SSK001
Choose the Seiko 5 Sports GMT SSK001 if you value Seiko In-House Automatic GMT technology, Made in Japan heritage, and 42.5mm proportions. At $250–$500, the Automatic Caliber 4R34 (True GMT) with 41 Hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Omega Seamaster Ploprof 1200M Co-Axial Master Chronometer 55 x 48mm 227.60.55.21.03.001 (titanium and Sedna gold, blue lacquered dial) and Seiko 5 Sports GMT SSK001 represent two distinct approaches to fine watchmaking — the Omega bringing Swiss Made tradition while Seiko delivers Made in Japan engineering.
Frequently Asked Questions
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How This Page Was Made
Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.