Updated
Casio Pro Trek PRW3500T-7 vs Seiko 5 Sports GMT SSK001
Casio's diver meets Seiko's GMT watch
Quick Verdict
The Casio Pro Trek PRW3500T-7 ($250–$500) and Seiko 5 Sports GMT SSK001 ($250–$500) are closely matched timepieces at similar price points. The Pro Trek PRW3500T-7 emphasizes Tough Solar Quartz, Multi-Band 6 engineering while the 5 Sports GMT SSK001 focuses on Made in Japan craftsmanship.
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Specifications Compared
| Feature | Casio Pro Trek PRW3500T-7 | Seiko 5 Sports GMT SSK001 |
|---|---|---|
| Price | $250–$500 | $250–$500 |
| Case Size | 56.9 × 53.4 × 14.8mm | 42.5mm |
| Movement | Tough Solar (Solar Quartz), Radio-Controlled | Automatic Caliber 4R34 (True GMT) |
| Caliber Type | Tough Solar Quartz, Multi-Band 6 | Seiko In-House Automatic GMT |
| Power Reserve | Tough Solar (Rechargeable) | 41 Hours |
| Water Resistance | 200m (20 ATM) | 100m (10 ATM) |
| Crystal | Mineral Glass | Hardlex Crystal |
| Case Material | Resin / Stainless Steel, Titanium Bracelet | Stainless Steel |
| Origin | Casio (Japan) | Made in Japan |
Category-by-Category Analysis
Design & Aesthetics
Casio's design language vs Seiko's approach
The Casio Pro Trek PRW3500T-7 features a Resin / Stainless Steel, Titanium Bracelet case at 56.9 × 53.4 × 14.8mm with Mineral Glass protection. The Seiko 5 Sports GMT SSK001 offers Stainless Steel construction at 42.5mm with Hardlex Crystal. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Tough Solar (Solar Quartz), Radio-Controlled vs Automatic Caliber 4R34 (True GMT)
The Pro Trek PRW3500T-7 runs the Tough Solar (Solar Quartz), Radio-Controlled (Tough Solar Quartz, Multi-Band 6, Tough Solar (Rechargeable) power reserve) at standard frequency. The 5 Sports GMT SSK001 uses the Automatic Caliber 4R34 (True GMT) (Seiko In-House Automatic GMT, 41 Hours reserve) at 21,600 vph (3 Hz). The 5 Sports GMT SSK001 offers a longer power reserve.
Wearability & Fit
56.9 × 53.4 × 14.8mm vs 42.5mm — different wrist presence
At 56.9 × 53.4 × 14.8mm, the Pro Trek PRW3500T-7 has a bolder wrist presence compared to the 5 Sports GMT SSK001 at 42.5mm. Water resistance differs: 200m (20 ATM) vs 100m (10 ATM).
Value & Cost of Ownership
Same tier — different value propositions
The Casio Pro Trek PRW3500T-7 sits at $250–$500 and the Seiko 5 Sports GMT SSK001 at $250–$500. On the specs that outlast any price: the Pro Trek PRW3500T-7 uses Mineral Glass with Tough Solar (Rechargeable), against Hardlex Crystal and 41 Hours on the 5 Sports GMT SSK001. Service intervals are typically 5-7 years for both.
Water Resistance
200m (20 ATM) vs 100m (10 ATM)
The Pro Trek PRW3500T-7 is rated to 200m (20 ATM) while the 5 Sports GMT SSK001 handles 100m (10 ATM). The Pro Trek PRW3500T-7 is better suited for water activities.
Our Verdict
Casio
Pro Trek PRW3500T-7
Choose the Casio Pro Trek PRW3500T-7 if you prioritize Tough Solar Quartz, Multi-Band 6 engineering, Casio (Japan) craftsmanship, and 200m (20 ATM) water resistance. At $250–$500, it delivers Tough Solar (Solar Quartz), Radio-Controlled with Tough Solar (Rechargeable) power reserve.
Check Price on AmazonSeiko
5 Sports GMT SSK001
Choose the Seiko 5 Sports GMT SSK001 if you value Seiko In-House Automatic GMT technology, Made in Japan heritage, and 42.5mm proportions. At $250–$500, the Automatic Caliber 4R34 (True GMT) with 41 Hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Casio Pro Trek PRW3500T-7 and Seiko 5 Sports GMT SSK001 represent two distinct approaches to fine watchmaking — the Casio bringing Casio (Japan) 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.