During the Falklands War in 1982, both Argentina and the United Kingdom made heavy use of light infantry and its doctrines during the campaign, most notably the Argentine 5th Naval Infantry Battalion (Argentina) and 25th Infantry Regiment (Argentina) and the British Parachute Regiment and Royal Marines of 3 Commando Brigade. Due to the rocky and mountainous terrain of the Falkland Islands, operations on the ground were only made possible with the use of light infantry because the use of mechanized infantry or armour was severely limited by of the terrain, leading to the "Yomp" across the Falklands, in which Royal Marines and Paras yomped (and tabbed) with their equipment across the islands, covering 56 miles (90 km) in three days carrying 80-pound (36 kg) loads after disembarking from ships at San Carlos on East Falkland, on 21 May 1982.