In 1969 I was with the 2bn 12th Marines in Vietnam our unit supported the 9th Marines with direct artillery support along with other support activities. I remember one time being out on post at the rock pile. We had a dirt hole with a dig out on the side of the hole that two men could lay inside and sleep while a third man stood watch (4hrs) with an M60 machine gun and a detonator attached to Claymore mines. Here is a picture of the group that I was with in hooch 11 in Dong-Ha.
12 Marine 3rd MARDIV