The 92d Military Police Battalion was tasked with providing security along the major Saigon river waterway from Saigon to its exit into the South China Sea at Vung Tau. As shown, the river was always full of ships carrying supplies into Saigon from where the rest of the country was supplied by air or road. These ships are all anchored at Nha Be, a holding area about 20 miles outside of Saigon awaiting pier space. Look closely and you can see the anchor chains holding the ships in place. On occasion, the Viet Cong would send swimmers into the river to attach mines to the anchor chains. As the ship lay at anchor, it would sometimes turn with the tide and if it crossed the anchor chain, BOOM. We patrolled the river by air and water and had several high-speed patrol boats (PBRs) which were like mini-PT boats. As some of the other photos show, we were not always successful in preventing the sinking of these supply ships.