Head-to-Head Comparison

Updated September 5, 2026

Casio MRW-230H vs Mido Ocean Star GMT

Casio's timepiece meets Mido's diver

Quick Verdict

The Casio MRW-230H (Under $50) offers Casio Quartz (Battery) precision in the tier below the Mido Ocean Star GMT ($1,000–$1,500). The MRW-230H measures 44.6mm (47.9 x 44.6 x 12.3mm) and is rated 100m (10 ATM). The Ocean Star GMT counters with Swiss Made craftsmanship and 200m (20 ATM) water resistance. Both are exceptional watches for their respective tiers.

CasioMRW-230HUnder $50 Check price MidoOcean Star GMT$1,000–$1,500 Check price

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Casio

MRW-230H

Under $50

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Mido

Ocean Star GMT

$1,000–$1,500

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Specifications Compared

Feature	Casio MRW-230H	Mido Ocean Star GMT
Price	Under $50	$1,000–$1,500
Case Size	44.6mm (47.9 x 44.6 x 12.3mm)	44mm
Movement	Quartz	Automatic Caliber 80 (Base ETA C07.661)
Caliber Type	Casio Quartz (Battery)	Automatic (ETA C07.661 base)
Power Reserve	Approx. 3-year battery (SR626SW)	80 Hours
Water Resistance	100m (10 ATM)	200m (20 ATM)
Crystal	Resin Glass	Sapphire with Double-sided AR
Case Material	Resin case, aluminum bezel ring	Stainless Steel
Origin	Casio (Japan)	Swiss Made

Category-by-Category Analysis

🎨

Design & Aesthetics

Edge: Draw

Casio's design language vs Mido's approach

The Casio MRW-230H features a Resin case, aluminum bezel ring case at 44.6mm (47.9 x 44.6 x 12.3mm) with Resin Glass protection. The Mido Ocean Star GMT offers Stainless Steel construction at 44mm with Sapphire with Double-sided AR. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Mido

Quartz vs Automatic Caliber 80 (Base ETA C07.661)

The MRW-230H runs the Quartz (Casio Quartz (Battery), Approx. 3-year battery (SR626SW) power reserve) at standard frequency. The Ocean Star GMT uses the Automatic Caliber 80 (Base ETA C07.661) (Automatic (ETA C07.661 base), 80 Hours reserve) at 21,600 vph (3 Hz). The Ocean Star GMT offers a longer power reserve.

📏

Wearability & Fit

Edge: Mido

44.6mm (47.9 x 44.6 x 12.3mm) vs 44mm — different wrist presence

At 44.6mm (47.9 x 44.6 x 12.3mm), the MRW-230H has a bolder wrist presence compared to the Ocean Star GMT at 44mm. Water resistance differs: 100m (10 ATM) vs 200m (20 ATM).

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Value & Cost of Ownership

Edge: Casio

Casio sits in the lower tier

The Casio MRW-230H sits at Under $50 and the Mido Ocean Star GMT at $1,000–$1,500. On the specs that outlast any price: the MRW-230H uses Resin Glass with Approx. 3-year battery (SR626SW), against Sapphire with Double-sided AR and 80 Hours on the Ocean Star GMT. Service intervals are typically 5-7 years for both.

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Water Resistance

Edge: Mido

100m (10 ATM) vs 200m (20 ATM)

The MRW-230H is rated to 100m (10 ATM) while the Ocean Star GMT handles 200m (20 ATM). The Ocean Star GMT offers superior water resistance.

Our Verdict

Casio

MRW-230H

Choose the Casio MRW-230H if you prioritize Casio Quartz (Battery) engineering, Casio (Japan) craftsmanship, and 100m (10 ATM) water resistance. At Under $50, it delivers Quartz with Approx. 3-year battery (SR626SW) power reserve.

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Mido

Ocean Star GMT

Choose the Mido Ocean Star GMT if you value Automatic (ETA C07.661 base) technology, Swiss Made heritage, and 44mm proportions. At $1,000–$1,500, the Automatic Caliber 80 (Base ETA C07.661) with 80 Hours power reserve makes it a compelling choice.

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The Bottom Line

The Casio MRW-230H and Mido Ocean Star GMT represent two distinct approaches to fine watchmaking — the Casio bringing Casio (Japan) tradition while Mido delivers Swiss Made engineering.

Frequently Asked Questions

The Mido Ocean Star GMT is the better buy if you want a mechanical movement; the Casio MRW-230H is the better buy if you want quartz accuracy with no servicing. For water, the Mido Ocean Star GMT is rated 200 m against 100 m, which is the difference between swimming and diving on one side and splashes on the other. On price, the Casio MRW-230H sits a band lower (Under $50 against $1,000–$1,500), 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 MRW-230H offers better upfront value, sitting a tier lower at Under $50. However, the Mido Ocean Star GMT may justify its premium with superior finishing, heritage, or resale value.

Both are suitable for daily wear. The MRW-230H at 44.6mm (47.9 x 44.6 x 12.3mm) with 100m (10 ATM) water resistance handles everyday situations. The Ocean Star GMT at 44mm with 200m (20 ATM) is similarly capable. The MRW-230H uses Resin Glass while the Ocean Star GMT uses Sapphire with Double-sided AR.

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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.