Head-to-Head Comparison

Updated September 5, 2026

Casio MRW-230H vs Citizen Promaster Air Nighthawk

Casio's timepiece meets Citizen's diver

Quick Verdict

The Casio MRW-230H (Under $50) offers Casio Quartz (Battery) precision in the tier below the Citizen Promaster Air Nighthawk ($250–$500). The MRW-230H measures 44.6mm (47.9 x 44.6 x 12.3mm) and is rated 100m (10 ATM). The Promaster Air Nighthawk counters with Citizen (Japan) craftsmanship and 200m (20 ATM) water resistance. Both are exceptional watches for their respective tiers.

CasioMRW-230HUnder $50 Check price CitizenPromaster Air Nighthawk$250–$500 Check price

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Casio

MRW-230H

Under $50

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Citizen

Promaster Air Nighthawk

$250–$500

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Specifications Compared

Feature	Casio MRW-230H	Citizen Promaster Air Nighthawk
Price	Under $50	$250–$500
Case Size	44.6mm (47.9 x 44.6 x 12.3mm)	42mm
Movement	Quartz	Eco-Drive Caliber B877
Caliber Type	Casio Quartz (Battery)	Eco-Drive Solar Quartz (No Battery Change)
Power Reserve	Approx. 3-year battery (SR626SW)	6 Months (Solar, Full Charge)
Water Resistance	100m (10 ATM)	200m (20 ATM)
Crystal	Resin Glass	Mineral Glass
Case Material	Resin case, aluminum bezel ring	Stainless Steel
Origin	Casio (Japan)	Citizen (Japan)

Category-by-Category Analysis

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Design & Aesthetics

Edge: Draw

Casio's design language vs Citizen'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 Citizen Promaster Air Nighthawk offers Stainless Steel construction at 42mm with Mineral Glass. Both represent their brand's distinct design philosophy and heritage.

⚙️

Movement & Performance

Edge: Citizen

Quartz vs Eco-Drive Caliber B877

The MRW-230H runs the Quartz (Casio Quartz (Battery), Approx. 3-year battery (SR626SW) power reserve) at standard frequency. The Promaster Air Nighthawk uses the Eco-Drive Caliber B877 (Eco-Drive Solar Quartz (No Battery Change), 6 Months (Solar, Full Charge) reserve) at standard. The Promaster Air Nighthawk offers a longer power reserve.

📏

Wearability & Fit

Edge: Citizen

44.6mm (47.9 x 44.6 x 12.3mm) vs 42mm — 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 Promaster Air Nighthawk at 42mm. 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 Citizen Promaster Air Nighthawk at $250–$500. On the specs that outlast any price: the MRW-230H uses Resin Glass with Approx. 3-year battery (SR626SW), against Mineral Glass and 6 Months (Solar, Full Charge) on the Promaster Air Nighthawk. Service intervals are typically 5-7 years for both.

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Water Resistance

Edge: Citizen

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

The MRW-230H is rated to 100m (10 ATM) while the Promaster Air Nighthawk handles 200m (20 ATM). The Promaster Air Nighthawk 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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Citizen

Promaster Air Nighthawk

Choose the Citizen Promaster Air Nighthawk if you value Eco-Drive Solar Quartz (No Battery Change) technology, Citizen (Japan) heritage, and 42mm proportions. At $250–$500, the Eco-Drive Caliber B877 with 6 Months (Solar, Full Charge) power reserve makes it a compelling choice.

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The Bottom Line

The Casio MRW-230H and Citizen Promaster Air Nighthawk represent two distinct approaches to fine watchmaking — the Casio bringing Casio (Japan) tradition while Citizen delivers Citizen (Japan) engineering.

Frequently Asked Questions

For water, the Citizen Promaster Air Nighthawk 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 $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 MRW-230H offers better upfront value, sitting a tier lower at Under $50. However, the Citizen Promaster Air Nighthawk 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 Promaster Air Nighthawk at 42mm with 200m (20 ATM) is similarly capable. The MRW-230H uses Resin Glass while the Promaster Air Nighthawk 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.