Casio G-Shock Men's 51mm GN1000B-1A Watch - Black

This good-looking timepiece is from the GULFMASTER series, designed and engineered to stand up to the rigors of maritime wear. It features a digital compass that takes continuous readings for 60 seconds to help find your bearings at sea, as well as a thermometer to keep you informed about the environment around you. Other versatile functions include the tide graph, moon data, a hand shift feature and more. With useful and highly practical features packed into a form that maintains all-day comfort, this model guarantees durability and performance, providing support to the men of the sea and their activities.


  • Casio G-Shock watches
  • Model no.: GN1000B-1A
  • For men
  • Movement: Japanese quartz
  • Dial colour: Black/Blue
  • Band colour: Black
  • Case material: Resin (stainless steel back)
  • Band material: Resin
  • Band measurement (approx. mm):
    • Width: 23
    • Length including the face: 240
  • Case diameter (approx. mm, includes casing): 51
  • Case thickness (approx. mm): 17
  • Clasp type: Buckle
  • Water resistance: 200M / 20BAR
  • 5 daily alarms
  • World time:
    • 29 time zones (29 cities + coordinated universal time)
    • Daylight saving on/off
  • LED light (super illuminator): Auto light switch, selectable illumination duration, afterglow
  • 1/100-second stopwatch
  • Full auto-calendar (to year 2099)
  • Neobrite
  • Shock resistant
  • Mineral glass
  • Digital compass (NORTH)
  • Moon data (moon age of the specific date, moon phase graph)
  • Tide graph (tide level for specific date and time)
  • Countdown timer
  • Hourly time signal
  • Button operation tone on/off
  • Hand shift feature (hands move out of the way to provide unobstructed view of display)
  • 12/24-hour format
  • Thermometer:
    • Display range: –10 to 60°C (14 to 140°F)
    • Display unit: 0.1°C (0.2°F)
  • Regular timekeeping:
    • Analog: 3 hands (hour, minute, second)
    • Digital: Hour, minute, second, pm, month, date, day
  • Accuracy: ±15 seconds per month
  • Battery type: SR927W x 2
  • Battery life: 2 years
  • Original box: Yes - ready for gift giving!
  • Designed in: N/A
  • Country of origin: Thailand
A Bit About The Brand / More Info

Casio has been crafting timeless designs for decades. Renowned for their combination of flair and versatility, Casio wrist watches are perfect for anyone who requires unique functionality to go.

Product Reviews


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15 April 2020

Product purchased as a birthday present. Looks great but can not comment on its use because it has not been used yet.

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17 November 2017


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14 September 2020

29 August 2020

13 August 2020