Oris Aquis Date Calibre 400 vs Seiko Prospex "Turtle"
Two divers compared — $2,500–$5,000 vs $500–$1,000
Quick Verdict
The Seiko Prospex "Turtle" ($500–$1,000) delivers In-House Automatic Manufacture technology in the tier below the Oris Aquis Date Calibre 400 ($2,500–$5,000). The Prospex "Turtle" measures 45mm and is rated 200m (20 ATM) Diver. The Aquis Date Calibre 400 justifies its premium with Swiss Made heritage and Automatic Calibre 400. Both represent excellent choices in the diver category.
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Specifications Compared
| Feature | Oris Aquis Date Calibre 400 | Seiko Prospex "Turtle" |
|---|---|---|
| Price | $2,500–$5,000 | $500–$1,000 |
| Case Size | 41.5mm | 45mm |
| Movement | Automatic Calibre 400 | Automatic Caliber 4R36 |
| Caliber Type | Oris In-House Manufacture | In-House Automatic Manufacture |
| Power Reserve | 120 Hours (5 Days) | 41 Hours |
| Water Resistance | 300m (30 ATM) | 200m (20 ATM) Diver |
| Crystal | Sapphire Crystal with Anti-Reflective Coating | Sapphire Crystal |
| Case Material | Stainless Steel | Stainless Steel |
| Origin | Swiss Made | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Oris's design language vs Seiko's approach
The Oris Aquis Date Calibre 400 features a Stainless Steel case at 41.5mm with Sapphire Crystal with Anti-Reflective Coating 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 Calibre 400 vs Automatic Caliber 4R36
The Aquis Date Calibre 400 runs the Automatic Calibre 400 (Oris In-House Manufacture, 120 Hours (5 Days) power reserve) at 28,800 vph (4 Hz) frequency. The Prospex "Turtle" uses the Automatic Caliber 4R36 (In-House Automatic Manufacture, 41 Hours reserve) at 21,600 vph (3 Hz). The Aquis Date Calibre 400 edges ahead on power reserve.
Wearability & Fit
41.5mm vs 45mm — different wrist presence
At 41.5mm, the Aquis Date Calibre 400 wears more compactly on smaller wrists compared to the Prospex "Turtle" at 45mm. Water resistance differs: 300m (30 ATM) vs 200m (20 ATM) Diver.
Value & Cost of Ownership
Seiko sits in the lower tier
The Oris Aquis Date Calibre 400 sits at $2,500–$5,000 and the Seiko Prospex "Turtle" at $500–$1,000. On the specs that outlast any price: the Aquis Date Calibre 400 uses Sapphire Crystal with Anti-Reflective Coating with 120 Hours (5 Days), against Sapphire Crystal and 41 Hours on the Prospex "Turtle". Service intervals are typically 5-7 years for both.
Water Resistance
300m (30 ATM) vs 200m (20 ATM) Diver
The Aquis Date Calibre 400 is rated to 300m (30 ATM) while the Prospex "Turtle" handles 200m (20 ATM) Diver. The Aquis Date Calibre 400 is better suited for water activities.
Our Verdict
Oris
Aquis Date Calibre 400
Choose the Oris Aquis Date Calibre 400 if you prioritize Oris In-House Manufacture engineering, Swiss Made craftsmanship, and 300m (30 ATM) water resistance. At $2,500–$5,000, it delivers Automatic Calibre 400 with 120 Hours (5 Days) 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 Oris Aquis Date Calibre 400 and Seiko Prospex "Turtle" represent two distinct approaches to the diver category — the Oris bringing Swiss Made tradition while Seiko delivers Made in Japan engineering.
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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.