Casio Pro Trek PRG340-1 vs Seiko Prospex Alpinist
Casio's timepiece meets Seiko's diver
Quick Verdict
The Casio Pro Trek PRG340-1 ($150–$250) offers Tough Solar Quartz (No Battery Change) precision in the tier below the Seiko Prospex Alpinist ($500–$1,000). The Pro Trek PRG340-1 measures 54.7 × 51.7 × 15.1mm and is rated 100m (10 ATM). The Prospex Alpinist counters with Made in Japan craftsmanship and 200m (20 ATM) water resistance. Both are exceptional watches for their respective tiers.
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Specifications Compared
| Feature | Casio Pro Trek PRG340-1 | Seiko Prospex Alpinist |
|---|---|---|
| Price | $150–$250 | $500–$1,000 |
| Case Size | 54.7 × 51.7 × 15.1mm | 39.5mm |
| Movement | Tough Solar (Solar Quartz) | Automatic Caliber 6R35 |
| Caliber Type | Tough Solar Quartz (No Battery Change) | In-House Automatic Manufacture |
| Power Reserve | Tough Solar (Rechargeable) | 70 Hours |
| Water Resistance | 100m (10 ATM) | 200m (20 ATM) |
| Crystal | Mineral Glass | Sapphire with Cyclops |
| Case Material | Bio-Based Resin | 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 PRG340-1 features a Bio-Based Resin case at 54.7 × 51.7 × 15.1mm with Mineral Glass protection. The Seiko Prospex Alpinist offers Stainless Steel construction at 39.5mm with Sapphire with Cyclops. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Tough Solar (Solar Quartz) vs Automatic Caliber 6R35
The Pro Trek PRG340-1 runs the Tough Solar (Solar Quartz) (Tough Solar Quartz (No Battery Change), Tough Solar (Rechargeable) power reserve) at standard frequency. The Prospex Alpinist uses the Automatic Caliber 6R35 (In-House Automatic Manufacture, 70 Hours reserve) at 21,600 vph (3 Hz). The Prospex Alpinist offers a longer power reserve.
Wearability & Fit
54.7 × 51.7 × 15.1mm vs 39.5mm — different wrist presence
At 54.7 × 51.7 × 15.1mm, the Pro Trek PRG340-1 has a bolder wrist presence compared to the Prospex Alpinist at 39.5mm. Water resistance differs: 100m (10 ATM) vs 200m (20 ATM).
Value & Cost of Ownership
Casio sits in the lower tier
The Casio Pro Trek PRG340-1 sits at $150–$250 and the Seiko Prospex Alpinist at $500–$1,000. On the specs that outlast any price: the Pro Trek PRG340-1 uses Mineral Glass with Tough Solar (Rechargeable), against Sapphire with Cyclops and 70 Hours on the Prospex Alpinist. Service intervals are typically 5-7 years for both.
Water Resistance
100m (10 ATM) vs 200m (20 ATM)
The Pro Trek PRG340-1 is rated to 100m (10 ATM) while the Prospex Alpinist handles 200m (20 ATM). The Prospex Alpinist offers superior water resistance.
Our Verdict
Casio
Pro Trek PRG340-1
Choose the Casio Pro Trek PRG340-1 if you prioritize Tough Solar Quartz (No Battery Change) engineering, Casio (Japan) craftsmanship, and 100m (10 ATM) water resistance. At $150–$250, it delivers Tough Solar (Solar Quartz) with Tough Solar (Rechargeable) power reserve.
Check Price on AmazonSeiko
Prospex Alpinist
Choose the Seiko Prospex Alpinist if you value In-House Automatic Manufacture technology, Made in Japan heritage, and 39.5mm proportions. At $500–$1,000, the Automatic Caliber 6R35 with 70 Hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Casio Pro Trek PRG340-1 and Seiko Prospex Alpinist 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.