Updated
Orient Kamasu vs Seiko Turtle
Two 200m Japanese automatic divers with sapphire
Quick Verdict
The Orient Kamasu ($250–$500) and the Seiko Prospex Turtle SRPE05 ($500–$1,000) are both 200m Japanese automatic divers with sapphire crystals and a day-date. The Kamasu is 41.8mm with a 40-hour reserve. The Turtle is 45mm with a 41-hour reserve and the classic cushion case. The specifications are close; the Kamasu is smaller and costs a band less.
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Specifications Compared
| Feature | Orient Kamasu Automatic Diver | Seiko Prospex "Turtle" |
|---|---|---|
| Price | $250–$500 | $500–$1,000 |
| Case Size | 41.8mm | 45mm |
| Movement | Automatic Caliber F6922 | Automatic Caliber 4R36 |
| Caliber Type | Orient In-House Automatic | In-House Automatic Manufacture |
| Power Reserve | 40 Hours | 41 Hours |
| Water Resistance | 200m (20 ATM) | 200m (20 ATM) Diver |
| Crystal | Sapphire Crystal | Sapphire Crystal |
| Case Material | Stainless Steel | Stainless Steel |
| Origin | Made in Japan | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Modern diver against the cushion classic
The Kamasu is a conventional modern diver. The Turtle's cushion case is one of Seiko's best-known shapes. If you want that shape, nothing else will do.
Movement & Performance
F6922 against 4R36
The Kamasu runs Orient's in-house F6922, 22 jewels, 40-hour reserve. The Turtle runs Seiko's 4R36, 24 jewels, 41-hour reserve. Both run at 21,600 vph and show the day and date. A tie.
Durability & Water Resistance
Same 200m, both sapphire
Both are rated to 200m (20 ATM) and both list sapphire crystals. On paper there is nothing between them.
Wearability & Fit
The Kamasu is 3.2mm smaller
The Kamasu is 41.8mm and the Turtle is 45mm. The Kamasu fits a wider range of wrists.
Value & Cost of Ownership
The Kamasu is a band cheaper
The Kamasu sits in the $250–$500 band and the Turtle in $500–$1,000. With near-identical specifications, the Kamasu is the better value.
Our Verdict
Orient
Kamasu Automatic Diver
Choose the Orient Kamasu if you want the most dive watch for the money. Its specification is almost the same as the Turtle's in a smaller, more wearable case.
View the dossierSeiko
Prospex "Turtle"
Choose the Seiko Turtle if you want the Prospex name and the iconic cushion case. It is a big watch at 45mm, so it suits larger wrists best.
Check Price on AmazonThe Bottom Line
The Orient Kamasu and the Seiko Prospex Turtle SRPE05 are both 200m automatic dive watches with sapphire crystals and a day-date, but the Kamasu is smaller at 41.8mm against 45mm and sits a price band lower.
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.