Updated
Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) vs Seiko Prospex "Turtle"
Omega's chronograph meets Seiko's diver
Quick Verdict
The Seiko Prospex "Turtle" ($500–$1,000) delivers In-House Automatic Manufacture technology in the tier below the Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) ($25,000+). The Prospex "Turtle" measures 45mm and is rated 200m (20 ATM) Diver. The Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) justifies its premium with Swiss Made heritage and Automatic, Omega Co-Axial Master Chronometer Calibre 8901. Both represent excellent choices in the luxury watch category.
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Specifications Compared
| Feature | Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) | Seiko Prospex "Turtle" |
|---|---|---|
| Price | $25,000+ | $500–$1,000 |
| Case Size | 43.5mm | 45mm |
| Movement | Automatic, Omega Co-Axial Master Chronometer Calibre 8901 | Automatic Caliber 4R36 |
| Caliber Type | Omega 8901, METAS Master Chronometer, anti-magnetic to 15,000 gauss | In-House Automatic Manufacture |
| Power Reserve | About 60 hours | 41 Hours |
| Water Resistance | 600m (60 ATM), helium escape valve | 200m (20 ATM) Diver |
| Crystal | Sapphire Crystal, sapphire caseback | Sapphire Crystal |
| Case Material | 18k Sedna gold | 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 Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) features a 18k Sedna gold case at 43.5mm with Sapphire Crystal, sapphire caseback protection. The Seiko Prospex "Turtle" offers Stainless Steel construction at 45mm with Sapphire Crystal. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Automatic, Omega Co-Axial Master Chronometer Calibre 8901 vs Automatic Caliber 4R36
The Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) runs the Automatic, Omega Co-Axial Master Chronometer Calibre 8901 (Omega 8901, METAS Master Chronometer, anti-magnetic to 15,000 gauss, About 60 hours power reserve) at standard frequency. The Prospex "Turtle" uses the Automatic Caliber 4R36 (In-House Automatic Manufacture, 41 Hours reserve) at 21,600 vph (3 Hz). The Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) edges ahead on power reserve.
Wearability & Fit
43.5mm vs 45mm — different wrist presence
At 43.5mm, the Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) wears more compactly on smaller wrists compared to the Prospex "Turtle" at 45mm. Water resistance differs: 600m (60 ATM), helium escape valve vs 200m (20 ATM) Diver.
Value & Cost of Ownership
Seiko sits in the lower tier
The Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) sits at $25,000+ and the Seiko Prospex "Turtle" at $500–$1,000. On the specs that outlast any price: the Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) uses Sapphire Crystal, sapphire caseback with About 60 hours, against Sapphire Crystal and 41 Hours on the Prospex "Turtle". Service intervals are typically 5-7 years for both.
Water Resistance
600m (60 ATM), helium escape valve vs 200m (20 ATM) Diver
The Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) is rated to 600m (60 ATM), helium escape valve while the Prospex "Turtle" handles 200m (20 ATM) Diver. The Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) is better suited for water activities.
Our Verdict
Omega
Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic)
Choose the Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) if you prioritize Omega 8901, METAS Master Chronometer, anti-magnetic to 15,000 gauss engineering, Swiss Made craftsmanship, and 600m (60 ATM), helium escape valve water resistance. At $25,000+, it delivers Automatic, Omega Co-Axial Master Chronometer Calibre 8901 with About 60 hours power reserve.
Check Price on AmazonSeiko
Prospex "Turtle"
Choose the Seiko Prospex "Turtle" if you value In-House Automatic Manufacture technology, Made in Japan heritage, and 45mm proportions. At $500–$1,000, the Automatic Caliber 4R36 with 41 Hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) and Seiko Prospex "Turtle" 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.