Casio G-Shock GMA-S2100 (small) vs Citizen Eco-Drive EP6050 (Promaster Diver)

Side-by-side comparison of specifications and features

CasioG-Shock

GMA-S2100 (small)

CitizenEco-Drive

EP6050 (Promaster Diver)

Key Differences

Best Value

Casio G-Shock (Ref. GMA-S2100 (small))

Starting from $124

Price Comparison

Casio G-Shock

MSRP

$150

New

$124

Used

$107

Citizen Eco-Drive

MSRP

$350

Used

$144

MSRP New (Amazon) Used (eBay)

Comparison of Casio G-Shock, Citizen Eco-Drive
Specification	Casio G-Shock	Citizen Eco-Drive
Pricing
MSRP	$150	$350
New Price	$124	N/A
Used Price (Low)	$107	$144
Used Price (High)	$866	$1,850
30-Day Trend	↑ +6.6%	↑ +1.1%
Used Price Range	$107 - $866	$144 - $1,850
Identity
Reference	GMA-S2100 (small)	EP6050 (Promaster Diver)
Nickname	N/A	N/A
Style	Ana-Digi, Sports, Tool	Diver, Tool, Sports
Release Era	1980s	1990s
Dimensions
Diameter	42.9mm	36mm
Thickness	11.2mm	N/A
Lug Width	N/A	N/A
Lug to Lug	46.2mm	N/A
Movement
Movement	Quartz	Solar Powered
Power Reserve / Battery	N/A	N/A
Accuracy	N/A	N/A
Case
Case Material	Resin	Stainless Steel
Crystal	Mineral Crystal	Mineral Crystal
Water Resistance	200m (diving)	200m (diving)
Bezel	Fixed	Unidirectional rotating
Dial
Dial Color	Black	Black
Luminous	Yes	Yes
Community
Review Rating	N/A	N/A
In Collections	N/A	N/A
On Wishlists	N/A	N/A
Forum Threads	N/A	N/A

Quick Summary

If you are deciding between Casio G-Shock GMA-S2100 (small) and Citizen Eco-Drive EP6050 (Promaster Diver), the real decision is usually about mechanical feel versus low-maintenance convenience, wrist presence versus easier fit, ana-digi character versus diver versatility. Start with fit first — case width and lug-to-lug usually matter more than secondary features if wrist comfort is a concern.

How to choose

The biggest practical difference is usually movement and upkeep. Start with wrist fit and movement preference, then use water resistance and price to break the tie.

Casio G-Shock GMA-S2100 (small)

Casio G-Shock GMA-S2100 (small) is a better fit for buyers who want more wrist presence, low-maintenance daily wear, ana-digi styling.

Citizen Eco-Drive EP6050 (Promaster Diver)

Citizen Eco-Drive EP6050 (Promaster Diver) is a better fit for smaller wrists, low-maintenance daily wear, diver styling.

Key Differences

Movement and upkeep

Casio G-Shock GMA-S2100 (small): quartz movement

Citizen Eco-Drive EP6050 (Promaster Diver): solar movement

Casio G-Shock GMA-S2100 (small) uses a quartz movement, while Citizen Eco-Drive EP6050 (Promaster Diver) uses a solar movement — that changes day-to-day ownership, upkeep, and the overall feel on the wrist.

Size and wearability

Casio G-Shock GMA-S2100 (small): 42.9mm · L2L 46.2mm · 41g

Citizen Eco-Drive EP6050 (Promaster Diver): 36mm

Fit is a real separator here — compare case width and lug-to-lug before deciding, especially if wrist comfort matters more than headline features.

Water resistance

Casio G-Shock GMA-S2100 (small): 200m

Citizen Eco-Drive EP6050 (Promaster Diver): 200m

Water resistance is similar on paper, so focus on fit, features, and price instead.

Price and value

Casio G-Shock GMA-S2100 (small): $124

Citizen Eco-Drive EP6050 (Promaster Diver): $191

There is a real price gap here — treat the more expensive option as an upgrade decision and confirm whether the extra spend buys something you will notice in weekly use.

Style and use case

Casio G-Shock GMA-S2100 (small): ana-digi

Citizen Eco-Drive EP6050 (Promaster Diver): diver

Casio G-Shock GMA-S2100 (small) leans more ana-digi, while Citizen Eco-Drive EP6050 (Promaster Diver) pulls toward diver use case — pick the one that matches how you will actually wear it.

Crystal and materials

Casio G-Shock GMA-S2100 (small): mineral crystal · resin

Citizen Eco-Drive EP6050 (Promaster Diver): mineral crystal · steel

Materials are broadly similar, so finish, fit, and price will matter more than the materials list alone.

Choose Casio G-Shock GMA-S2100 (small) If...

You prefer more dial presence and a larger case feel.
You want a lower-maintenance daily watch.
You are specifically shopping for a ana-digi style watch.

Choose Citizen Eco-Drive EP6050 (Promaster Diver) If...

You want a smaller case footprint on the wrist.
You want a lower-maintenance daily watch.
You are specifically shopping for a diver style watch.

Price and Value Notes

Casio G-Shock GMA-S2100 (small) is often the value play at current pricing, while Citizen Eco-Drive EP6050 (Promaster Diver) makes more sense if you will use its extra features regularly.

There is a real price gap here — treat the more expensive option as an upgrade decision and confirm whether the extra spend buys something you will notice in weekly use.

Where to Check Deals

Check current deals on Amazon and eBay using the buttons below — listing prices, seller quality, and condition can change quickly.

Check current deals on Amazon and eBay

Prices change often, so compare the latest listings and condition options before you buy.

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Casio G-Shock

Check Price on AmazonOpens in new tab · Price may vary

Check Price on eBayFrom $140 · Live listings

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Citizen Eco-Drive

Check Price on AmazonOpens in new tab · Price may vary

Check Price on eBayFrom $191 · Live listings

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Comparison FAQ

Which movement is easier to live with day to day?

Quartz and solar models are usually easier for grab-and-go use, while automatic and manual watches appeal more to buyers who enjoy the mechanical side of watch ownership.

Which one is better for smaller wrists?

Citizen Eco-Drive EP6050 (Promaster Diver) — it is 36mm wide versus 42.9mm.

Which is better for swimming or rough daily wear?

They are rated the same, so water resistance will not decide this. Choose on strap material and how much you mind scratching the case.

Is the more expensive one worth it?

Casio G-Shock GMA-S2100 (small) is the value pick at roughly $67 less. Pay more only if a specific difference above matters to you — otherwise the cheaper one is the smarter buy. Confirm live listings, since marketplace pricing moves.