This Campaign period was from 1 July 1966 to 31 May 1967. The growing Coastal Force devoted most of its attention to amphibious raids, patrols of shallow inlets and river mouths, troop lifts, and blocking support for allied ground sweeps. For instance, during Operation Irving in October 1966, ground forces and junk units in II Coastal Zone killed 681 Viet Cong troops. In addition, the junkmen established a government presence among the fishermen and provided them with medical services and other assistance. Sometimes the Coastal Force sailors convinced Communist soldiers to desert their units.
The enemy, who often attacked the 27 vulnerable Coastal Force bases, overran the triangular-shaped fortifications of Coastal Group 15 at Cua An Hoa in July 1965 and of Coastal Group 16 at Co Luy in August 1967. Other bases, however, withstood repeated assaults. In doing so, these facilities played a part in the allied effort that denied the enemy easy access to the coastal regions.
Viet Cong mines also took their toll of the command's MLMS fleet, which worked to keep open the shipping channel to Saigon. In August 1966 and again in January 1967, enemy mines sank an MLMS in the Rung Sat. The River Force did not fully employ its strength. The political troubles of 1965 and 1966 in the Republic of Vietnam, in which high-ranking River Force officers figured prominently, damaged morale and distracted personnel from their military mission.
The navy and the army rarely launched joint amphibious assaults against the Viet Cong. Operations reflected the River Force's lack of technically skilled crewmen, the poor maintenance and repair of river craft, and the absence of inspired leadership. Usually, only half of the command's units were ready for combat action, and many of these boats were committed by the army to static guard, resupply, troop lift, or other nonoffensive duties.
The reliance on defense over offense reflected the historic Vietnamese strategy of husbanding resources until there was clear advantage over an enemy. The Vietnamese Navy's River Force sailors often fought hard and bravely, killing many of the enemy and suffering heavy losses of their own, but their valor and sacrifice was not rewarded with strategic success.