More Royal Marines from 42 Commando have left the South West for a six-month deployment in Afghanistan.
About 200 commandos left their base at Bickleigh near Plymouth on Friday night to join more than 400 unit members who are already in Helmand Province.
It is the fourth tour of duty in Afghanistan for some of the Devon marines.
The marines are part of 3 Commando Brigade, which also includes the Army, Territorial Army and the Royal Navy.
Lt Col Ewen Murchison, commanding officer of 42 Commando, said the marines would be working with the Afghan national security forces in the Nad Ali district of Helmand Province.
When 42 Commando was in Afghanistan in 2008-09, three Royal Marines lost their lives.
Lt Col Murchison, said although the commandos had had two full years to train and prepare, the threat from insurgents remained.
"Clearly there is danger and there might be casualties, but we're ready to deal with those," he said.
Army personnel in Helmand are from 29 Commando Regiment Royal Artillery, based at the Citadel in Plymouth, 24 Commando Engineer Regiment from Chivenor and 1 Rifles (incorporating the former Devon and Dorset regiment) which recruits soldiers from across the South West.
The TA soldiers are from Exeter-based 6 Rifles, while the Royal Navy has personnel from 854 and 857 Naval Air Squadrons from Culdrose in Cornwall.