Casio G-Shock Watches G-Shock Authorised Dealer Tactical Gear Australia. A 10-year battery life, 10-bar water resistance and 10-meter dropping shock resistance. These were the three requirements of the “Triple 10” concept that led to development G-SHOCK's shock-resistant structure. The rugged shape and robust styling originated with an engineer's brief calling for an "unbreakable watch". Since its birth in 1983, G-SHOCK has continued its unrestrained evolution while retaining its unique basic structure. Today, G-SHOCK continues to take up challenges beyond the limits of time and common sense.