Casio G-Shock DW-5600 Square vs Seiko Prospex Samurai SRPF03
Two divers compared — $50–$100 vs $250–$500
Quick Verdict
The Casio G-Shock DW-5600 Square ($50–$100) offers Casio Digital Quartz (Battery) precision in the tier below the Seiko Prospex Samurai SRPF03 ($250–$500). The G-Shock DW-5600 Square measures 42.8mm (Square) and is rated 200m (20 ATM). The Prospex Samurai SRPF03 counters with Japanese Movement craftsmanship and 200m (20 ATM) water resistance. Both are exceptional divers for their respective tiers.
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Specifications Compared
| Feature | Casio G-Shock DW-5600 Square | Seiko Prospex Samurai SRPF03 |
|---|---|---|
| Price | $50–$100 | $250–$500 |
| Case Size | 42.8mm (Square) | 43.8mm |
| Movement | Quartz Module 3229 | Automatic Caliber 4R35 |
| Caliber Type | Casio Digital Quartz (Battery) | Seiko Automatic, hand-winding and hacking |
| Power Reserve | 2-Year Battery | 41 Hours |
| Water Resistance | 200m (20 ATM) | 200m (20 ATM) |
| Crystal | Mineral Glass | Hardlex Crystal |
| Case Material | Resin | Stainless Steel |
| Origin | Casio (Japan) | Japanese Movement |
Category-by-Category Analysis
Design & Aesthetics
Casio's design language vs Seiko's approach
The Casio G-Shock DW-5600 Square features a Resin case at 42.8mm (Square) with Mineral Glass protection. The Seiko Prospex Samurai SRPF03 offers Stainless Steel construction at 43.8mm with Hardlex Crystal. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Quartz Module 3229 vs Automatic Caliber 4R35
The G-Shock DW-5600 Square runs the Quartz Module 3229 (Casio Digital Quartz (Battery), 2-Year Battery power reserve) at standard frequency. The Prospex Samurai SRPF03 uses the Automatic Caliber 4R35 (Seiko Automatic, hand-winding and hacking, 41 Hours reserve) at 21,600 vph (3 Hz). The Prospex Samurai SRPF03 offers a longer power reserve.
Wearability & Fit
42.8mm (Square) vs 43.8mm — different wrist presence
At 42.8mm (Square), the G-Shock DW-5600 Square wears more compactly on smaller wrists compared to the Prospex Samurai SRPF03 at 43.8mm. Water resistance differs: 200m (20 ATM) vs 200m (20 ATM).
Value & Cost of Ownership
Casio sits in the lower tier
The Casio G-Shock DW-5600 Square sits at $50–$100 and the Seiko Prospex Samurai SRPF03 at $250–$500. On the specs that outlast any price: the G-Shock DW-5600 Square uses Mineral Glass with 2-Year Battery, against Hardlex Crystal and 41 Hours on the Prospex Samurai SRPF03. Service intervals are typically 5-7 years for both.
Water Resistance
200m (20 ATM) vs 200m (20 ATM)
The G-Shock DW-5600 Square is rated to 200m (20 ATM) while the Prospex Samurai SRPF03 handles 200m (20 ATM). Both offer identical water resistance ratings.
Our Verdict
Casio
G-Shock DW-5600 Square
Choose the Casio G-Shock DW-5600 Square if you prioritize Casio Digital Quartz (Battery) engineering, Casio (Japan) craftsmanship, and 200m (20 ATM) water resistance. At $50–$100, it delivers Quartz Module 3229 with 2-Year Battery power reserve.
Check Price on AmazonSeiko
Prospex Samurai SRPF03
Choose the Seiko Prospex Samurai SRPF03 if you value Seiko Automatic, hand-winding and hacking technology, Japanese Movement heritage, and 43.8mm proportions. At $250–$500, the Automatic Caliber 4R35 with 41 Hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Casio G-Shock DW-5600 Square and Seiko Prospex Samurai SRPF03 represent two distinct approaches to the diver category — the Casio bringing Casio (Japan) tradition while Seiko delivers Japanese Movement 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.