Head-to-Head Comparison

Updated September 5, 2026

Casio MRW-230H vs Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic)

Casio's timepiece meets Omega's chronograph

Quick Verdict

The Casio MRW-230H (Under $50) offers Casio Quartz (Battery) precision in the tier below the Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) ($25,000+). The MRW-230H measures 44.6mm (47.9 x 44.6 x 12.3mm) and is rated 100m (10 ATM). The Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) counters with Swiss Made craftsmanship and 600m (60 ATM), helium escape valve water resistance. Both are exceptional watches for their respective tiers.

CasioMRW-230HUnder $50 Check price OmegaSeamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic)$25,000+ Check price

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Casio

MRW-230H

Under $50

Check Price Full Review

Omega

Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic)

$25,000+

Check Price Full Review

Specifications Compared

Feature	Casio MRW-230H	Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic)
Price	Under $50	$25,000+
Case Size	44.6mm (47.9 x 44.6 x 12.3mm)	43.5mm
Movement	Quartz	Automatic, Omega Co-Axial Master Chronometer Calibre 8901
Caliber Type	Casio Quartz (Battery)	Omega 8901, METAS Master Chronometer, anti-magnetic to 15,000 gauss
Power Reserve	Approx. 3-year battery (SR626SW)	About 60 hours
Water Resistance	100m (10 ATM)	600m (60 ATM), helium escape valve
Crystal	Resin Glass	Sapphire Crystal, sapphire caseback
Case Material	Resin case, aluminum bezel ring	18k Sedna gold
Origin	Casio (Japan)	Swiss Made

Category-by-Category Analysis

🎨

Design & Aesthetics

Edge: Draw

Casio's design language vs Omega'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 Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) offers 18k Sedna gold construction at 43.5mm with Sapphire Crystal, sapphire caseback. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Omega

Quartz vs Automatic, Omega Co-Axial Master Chronometer Calibre 8901

The MRW-230H runs the Quartz (Casio Quartz (Battery), Approx. 3-year battery (SR626SW) power reserve) at standard frequency. The Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) uses the Automatic, Omega Co-Axial Master Chronometer Calibre 8901 (Omega 8901, METAS Master Chronometer, anti-magnetic to 15,000 gauss, About 60 hours reserve) at standard. The Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) offers a longer power reserve.

📏

Wearability & Fit

Edge: Omega

44.6mm (47.9 x 44.6 x 12.3mm) vs 43.5mm — 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 Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) at 43.5mm. Water resistance differs: 100m (10 ATM) vs 600m (60 ATM), helium escape valve.

💰

Value & Cost of Ownership

Edge: Casio

Casio sits in the lower tier

The Casio MRW-230H sits at Under $50 and the Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) at $25,000+. On the specs that outlast any price: the MRW-230H uses Resin Glass with Approx. 3-year battery (SR626SW), against Sapphire Crystal, sapphire caseback and About 60 hours on the Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic). Service intervals are typically 5-7 years for both.

💧

Water Resistance

Edge: Omega

100m (10 ATM) vs 600m (60 ATM), helium escape valve

The MRW-230H is rated to 100m (10 ATM) while the Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) handles 600m (60 ATM), helium escape valve. The Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) 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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Omega

Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic)

Choose the Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) if you value Omega 8901, METAS Master Chronometer, anti-magnetic to 15,000 gauss technology, Swiss Made heritage, and 43.5mm proportions. At $25,000+, the Automatic, Omega Co-Axial Master Chronometer Calibre 8901 with About 60 hours power reserve makes it a compelling choice.

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The Bottom Line

The Casio MRW-230H and Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) represent two distinct approaches to fine watchmaking — the Casio bringing Casio (Japan) tradition while Omega delivers Swiss Made engineering.

Frequently Asked Questions

The Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) 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 Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) is rated 600 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 $25,000+), 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 Omega Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) 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 Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) at 43.5mm with 600m (60 ATM), helium escape valve is similarly capable. The MRW-230H uses Resin Glass while the Seamaster Planet Ocean 600M 43.5mm (Sedna gold, blue ceramic) uses Sapphire Crystal, sapphire caseback.

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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.