The G6 Marksman is a Self-Propelled Anti-Aircraft Gun (SPAAG) system combining the chassis of the South African 6x6 wheeled G6 self-propelled howitzer with the "Marksman" defense system made up of 2 x 35mm Oerlikon autocannons and a Marconi radar system. With a fully-traversing turret, the vehicle is capable of engaging incoming low-flying targets such as helicopters and strike aircraft. It is comparable in battlefield role to the famous Soviet Cold War-era ZSU-23-4 "Shilka" vehicle.
The British G6 Marksman vehicle utilizes a crew of three (driver, gunner and commander) and carries 460 fragmenting projectiles as well as 40 Anti-Tank (AT) projectiles - the latter to be used against armored land vehicles if pressed. The vehicle is protected against 14.5mm heavy-caliber small arms fire as well as artillery spray from up to 155mm weapons. It carries eight electrically-operated smoke grenade dischargers to provide its own smokescreen. Power is served from an air-cooled diesel engine of 525 horsepower output with drive to all three axles. Road speeds reach 50 miles per hour with an operational road range out to 430 miles.
The Marksman system has also been installed on the chassis of the Soviet T-55Am by Finland to produce the "ltPsv 90" SPAAG series. These are powered by the V-55 V12 diesel-fueled engine of 620 horsepower and retain the T-55's tracked chassis and torsion bar suspension system.
While proposed on several other chassis - including the British Centurion, Chieftain and Challenger 1 MBT chassis - the Marksman only exists as the two aforementioned forms.