Updated
Orient Kamasu vs Seiko 5 Sports
Two Japanese automatic divers in the same band
Quick Verdict
The Orient Kamasu and the Seiko 5 Sports SRPD55 both sit in the $250–$500 band and both run in-house Japanese automatics with a day-date and about 40 hours of reserve. The Kamasu adds a sapphire crystal and a 200m rating in a 41.8mm case. The Seiko 5 Sports has Hardlex and 100m in a 42.5mm case. On specification, the Kamasu wins.
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Specifications Compared
| Feature | Orient Kamasu Automatic Diver | Seiko 5 Sports 5KX |
|---|---|---|
| Price | $250–$500 | $250–$500 |
| Case Size | 41.8mm | 42.5mm |
| Movement | Automatic Caliber F6922 | Automatic Caliber 4R36 |
| Caliber Type | Orient In-House Automatic | Seiko In-House Automatic |
| Power Reserve | 40 Hours | 41 Hours |
| Water Resistance | 200m (20 ATM) | 100m (10 ATM) |
| Crystal | Sapphire Crystal | Hardlex Crystal |
| Case Material | Stainless Steel | Stainless Steel |
| Origin | Made in Japan | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Two diver-style watches
Both are dive-style sports watches with a day-date. The Kamasu is the more polished diver; the Seiko 5 Sports is the more casual sports watch. This one is down to which dial you like.
Movement & Performance
F6922 against 4R36
The Kamasu runs Orient's in-house F6922, 22 jewels at 21,600 vph, with a 40-hour reserve. The Seiko runs its in-house 4R36, 24 jewels at 21,600 vph, with a 41-hour reserve. Both show the day and date. Functionally a tie.
Durability & Water Resistance
Sapphire and 200m against Hardlex and 100m
The Kamasu has a sapphire crystal and a 200m (20 ATM) rating. The Seiko 5 Sports has Hardlex, Seiko's hardened mineral glass, and a 100m (10 ATM) rating. This is the clearest difference between them, and it favours the Orient.
Wearability & Fit
Nearly the same size
The Kamasu is 41.8mm and the Seiko is 42.5mm. Less than a millimetre apart; both are mid-to-large sports watches.
Value & Cost of Ownership
More specification for the same band
Both sit in the $250–$500 band. Within that band, the Kamasu gives you sapphire and 200m. That makes it the better value on paper.
Our Verdict
Orient
Kamasu Automatic Diver
Choose the Orient Kamasu if you want the stronger specification for similar money. Sapphire and 200m are real upgrades over the Seiko, and the case is slightly smaller.
View the dossierSeiko
5 Sports 5KX
Choose the Seiko 5 Sports if you prefer its styling. It is fully capable for swimming at 100m, and the 4R36 is a well-known workhorse.
Check Price on AmazonThe Bottom Line
The Orient Kamasu and the Seiko 5 Sports SRPD55 are both Japanese automatic dive-style watches in the $250 to $500 band, but the Kamasu has a sapphire crystal and 200m water resistance, while the Seiko 5 Sports has a Hardlex crystal and 100m.
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.