# Casio G-Shock GA-2100 Review by A.I. WatchMetrics

## Watch Summary
The Casio G-Shock GA-2100, affectionately nicknamed the "CasiOak," is a tough sports-tool watch featuring a slim octagonal carbon-reinforced resin case with integrated analog-digital display, designed for the active everyday wearer who demands shock resistance, 200m water resistance, and multifunction utility without bulk, powered by the reliable quartz Module 5611 offering about 3 years of battery reserve on a CR2016.

## Overall Watch Rating: 6.1/10.0

**Functions Metric (8.5/10.0)** - Packed with world time for 38 cities, 5 alarms, 1/100-second stopwatch, and countdown timer, it matches the utility of pricier Seiko or Citizen quartz divers.
**Versatility Metric (8.2/10.0)** - Its slim profile, lightweight build, and broad functionality make it equally at home in casual, sports, adventure, or travel scenarios, outperforming chunkier G-Shocks for daily wear.
**History & Innovation Metric (7.8/10.0)** - Building on G-Shock's 40-year legacy of unbreakable toughness pioneered in 1983, the Carbon Core Guard adds modern lightweight strength akin to established tool watch brands.
**Dials & Design Metric (7.5/10.0)** - The minimalist black dial with clear analog hands and digital window in an iconic octagonal bezel delivers a fresh, stealthy aesthetic comparable to entry-level integrated sports watches.
**Complications Metric (6.8/10.0)** - World time, stopwatch, and alarms provide solid everyday complications on par with mid-tier quartz chronographs from Timex or Citizen.
**Brand Metric (5.2/10.0)** - Casio's G-Shock line offers reliable mid-tier durability and innovation, solid like Hamilton or Seiko but without luxury prestige.
**Movement Metric (5.0/10.0)** - The Module 5611 quartz delivers precise timekeeping and shock resistance on average with other mass-market quartz movements from Citizen or Seiko.
**Material Metric (3.8/10.0)** - Resin case and crystal prioritize lightweight toughness over premium feel, falling short of even entry-level stainless steel like in Timex Ironman.
**Rarity Metric (1.8/10.0)** - Widely available at mass-market prices with high production volumes, it lacks the scarcity of limited-edition microbrands or vintage pieces.

## Total Performance Score (TPS): 4.1

## WM Collector Grade: C

## Performance Insights: Excels in functions, versatility, and history with unbeatable everyday toughness, but basic materials and ubiquity limit appeal versus implied price expectations for more refined tools.

## TPS Interpretation: Average Value: The watch provides robust multifunction performance and iconic style at a budget price, ideal for practical use but not collector investment.

## Watch Data
[Picture URL] - https://gshock.casio.com/content/dam/gshock/us/en/product/ga-2100/ga-2100-1a/GA-2100-1A_Main.png; [backPicture] - https://gshock.casio.com/content/dam/gshock/us/en/product/ga-2100/ga-2100-1a/GA-2100-1A_Back.png; [lumePicture] - none; [Nickname] - CasiOak; [Brand] - Casio; [Model] - G-Shock GA-2100; [Country] - Japan; [Product Link] - https://gshock.casio.com/us/watches/gshock/product.GA-2100-1A/; [reviewLink] - ; [Movement Type] - Quartz; [Movement Name] - Module 5611; [# Secondary] - 1; [watchDescription] - Slim octagonal G-Shock with analog-digital display, shock resistant, Carbon Core Guard resin case; [caseWidth] - 48.5; [lugToLugLength] - 52.0; [thickness] - 11.8; [lug] - 25; [waterResist] - 200; [powerReserve] - 3 years; [beatFrequency] - 32768; [lume] - none; [jewels] - 0; [caseMaterial] - Carbon fiber reinforced resin; [watchGlass] - Resin; [Bezel] - Fixed octagonal resin; [caseback] - Solid screw-down resin; [Crown] - Push buttons; [Strap] - Resin; [Shape] - Octagonal tonneau; [Dial] - Analog-digital black; [Seconds] - Yes; [Date] - Yes; [Calendar] - No; [Chiming] - No; [Chronograph] - Yes; [Compass] - No; [dateCompilation] - No; [DigitalDisplay] - Yes; [Dress] - No; [Field] - No; [GMT] - No; [Mechanical Alarm] - No; [Moonphase] - No; [Tourbillon] - No; [worldTimer] - Yes; [powerReserveIndicator] - No; [Diver] - No; [Pilot] - No; [racing] - No; [Skeleton] - No; [Vintage] - No; [StyleFormal] - No; [StyleCasual] - Yes; [StyleSports] - Yes; [StyleTravel] - Yes; [StyleAdventure] - Yes; [StyleCollector] - Yes; [StyleTool] - Yes; [StyleStatement] - Yes; [StyleVintage] - No; [StyleSmart] - No; [StyleCustom] - No; [TPS_new] - 4.1; [TPSgrade] - C; [TPSimpliedPrice] - 185;

**A.I. WatchMetrics Review v37.4 Grok 4 Fast. December 19, 2025.**