Head-to-Head Comparison

Updated September 5, 2026

Citizen Promaster Sea Eco-Drive Diver vs Casio G-Shock DW-5600 Square

Two divers compared — $250–$500 vs $50–$100

Quick Verdict

The Casio G-Shock DW-5600 Square ($50–$100) delivers Casio Digital Quartz (Battery) technology in the tier below the Citizen Promaster Sea Eco-Drive Diver ($250–$500). The G-Shock DW-5600 Square measures 42.8mm (Square) and is rated 200m (20 ATM). The Promaster Sea Eco-Drive Diver justifies its premium with Made in Japan heritage and Eco-Drive Caliber E168. Both represent excellent choices in the diver category.

CitizenPromaster Sea Eco-Drive Diver$250–$500 Check price CasioG-Shock DW-5600 Square$50–$100 Check price

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Citizen

Promaster Sea Eco-Drive Diver

$250–$500

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Casio

G-Shock DW-5600 Square

$50–$100

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Specifications Compared

Feature	Citizen Promaster Sea Eco-Drive Diver	Casio G-Shock DW-5600 Square
Price	$250–$500	$50–$100
Case Size	44mm	42.8mm (Square)
Movement	Eco-Drive Caliber E168	Quartz Module 3229
Caliber Type	Citizen Eco-Drive (Solar Quartz)	Casio Digital Quartz (Battery)
Power Reserve	—	2-Year Battery
Water Resistance	200m (20 ATM) ISO 6425	200m (20 ATM)
Crystal	Mineral Crystal	Mineral Glass
Case Material	Stainless Steel	Resin
Origin	Made in Japan	Casio (Japan)

Category-by-Category Analysis

🎨

Design & Aesthetics

Edge: Draw

Citizen's design language vs Casio's approach

The Citizen Promaster Sea Eco-Drive Diver features a Stainless Steel case at 44mm with Mineral Crystal protection. The Casio G-Shock DW-5600 Square offers Resin construction at 42.8mm (Square) with Mineral Glass. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Casio

Eco-Drive Caliber E168 vs Quartz Module 3229

The Promaster Sea Eco-Drive Diver runs the Eco-Drive Caliber E168 (Citizen Eco-Drive (Solar Quartz), standard power reserve) at standard frequency. The G-Shock DW-5600 Square uses the Quartz Module 3229 (Casio Digital Quartz (Battery), 2-Year Battery reserve) at standard. The G-Shock DW-5600 Square offers a longer power reserve.

📏

Wearability & Fit

Edge: Casio

44mm vs 42.8mm (Square) — different wrist presence

At 44mm, the Promaster Sea Eco-Drive Diver has a bolder wrist presence compared to the G-Shock DW-5600 Square at 42.8mm (Square). Water resistance differs: 200m (20 ATM) ISO 6425 vs 200m (20 ATM).

💰

Value & Cost of Ownership

Edge: Casio

Casio sits in the lower tier

The Citizen Promaster Sea Eco-Drive Diver sits at $250–$500 and the Casio G-Shock DW-5600 Square at $50–$100. On the specs that outlast any price: the Promaster Sea Eco-Drive Diver uses Mineral Crystal with a standard reserve, against Mineral Glass and 2-Year Battery on the G-Shock DW-5600 Square. Service intervals are typically 5-7 years for both.

💧

Water Resistance

Edge: Draw

200m (20 ATM) ISO 6425 vs 200m (20 ATM)

The Promaster Sea Eco-Drive Diver is rated to 200m (20 ATM) ISO 6425 while the G-Shock DW-5600 Square handles 200m (20 ATM). Both offer identical water resistance ratings.

Our Verdict

Citizen

Promaster Sea Eco-Drive Diver

Choose the Citizen Promaster Sea Eco-Drive Diver if you prioritize Citizen Eco-Drive (Solar Quartz) engineering, Made in Japan craftsmanship, and 200m (20 ATM) ISO 6425 water resistance. At $250–$500, it delivers Eco-Drive Caliber E168 with solid power reserve.

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Casio

G-Shock DW-5600 Square

Choose the Casio G-Shock DW-5600 Square if you value Casio Digital Quartz (Battery) technology, Casio (Japan) heritage, and 42.8mm (Square) proportions. At $50–$100, the Quartz Module 3229 with 2-Year Battery power reserve makes it a compelling choice.

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The Bottom Line

The Citizen Promaster Sea Eco-Drive Diver and Casio G-Shock DW-5600 Square represent two distinct approaches to the diver category — the Citizen bringing Made in Japan tradition while Casio delivers Casio (Japan) engineering.

Frequently Asked Questions

On price, the Casio G-Shock DW-5600 Square sits a band lower ($50–$100 against $250–$500), so it is the cheaper way into the category. Neither is better at everything; the spec table above shows movement, case size, water resistance and crystal side by side so you can weigh what matters to you. We do not test units, so this is the makers' data, not a bench result.

The Casio G-Shock DW-5600 Square offers better upfront value, sitting a tier lower at $50–$100. However, the Citizen Promaster Sea Eco-Drive Diver may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The Promaster Sea Eco-Drive Diver at 44mm with 200m (20 ATM) ISO 6425 water resistance handles everyday situations. The G-Shock DW-5600 Square at 42.8mm (Square) with 200m (20 ATM) is similarly capable. The Promaster Sea Eco-Drive Diver uses Mineral Crystal while the G-Shock DW-5600 Square uses Mineral Glass.

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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.