The U.S. Navy officially created Operation Game Warden in December 1965, however actual patrols did not officially begin until February of the next year. When the operation took effect the Navy divided Task Force 116 into two separate task groups and assigned them to specific regions within the Delta. Task Group 116.1, a force of 80 PBRs, patrolled the heart of the Mekong Delta and operated out of river's edge bases in
Mỹ Tho,
Vĩnh Long,
Cần Thơ,
Sa Đéc, and
Long Xuyên. Task Group 116.2, was roughly half the size and guarded the Rung Sat Special Zone using base areas in
Nhà Bè and
Cat Lo. Task Force 116 focused on instituting a curfew on all waterways for the first months of action, hence devoting much of its time to searching Vietnamese
sampans and
junks on the river. During this time the sailors and PBRs stuck to strict
rules of engagement that permitted the boats to use deadly force only after fired upon by the enemy, but as time went on tactics on both sides changed. Not only did the VC adapt to frequent daytime patrols by conducting a majority of their operations at night to use the cover of dark, but they also attempted to blend in with heavy commercial traffic during peak daylight hours. Correspondingly, the communist forces began to hide contraband, including weapons and supplies, beneath false-bottomed floors and on the underside of their sampans. Patrolling of the Rung Sat Special Zone was particularly difficult for Task Group 116.2, due to the large open areas on the
South China Sea as well as the maze-like meanderings of the Long Tau River through the sector. These factors granted the VC with ample opportunities to plant mines in hopes of obstructing traffic. The mining of the Panamanian ship SS Eastern Mariner, along with the attempted mining of two other ships in
Nha Be, on 26 May 1966 merely underlined the substandard security in the area during the early operations of Game Warden. The tactics employed by Task Force 116 followed a general framework during Operation Game Warden, however several adaptations were instituted to properly deal with constantly changing enemy strategies as well the treacherous terrain. Patrol boats would frequently pair up and travel in a
column formation about 400–600 yards apart, a distance close enough to cover one another but far enough away to increase the effectiveness of their radars while also minimizing the threat of an effective riverside ambush. Similar to most patrolling missions, the PBRs would approach suspicious watercraft from an angle that maximized the number of weapons the boat could bear on the potential target. Searches were carried out as close to midstream as possible in order to minimize the PBRs vulnerability to surprise attacks from the riverbanks. Once the nighttime curfew was in effect, encounters occurring at night were more likely than not hostile. Task Force 116 developed numerous effective tactics throughout Operation Game Warden including the silent or drifting patrol, which called for the PBRs to speed into their patrol zone upstream, cut the engines, and allow the current to carry them through their assigned sections of river in hopes of catching the enemy off guard. Unlike other units, much of Task Force 116's development came from trial and error since it had no predecessor to draw intelligence or tactics from. For example, LSTs were primarily positioned in the South China Sea near the river mouths, however this proved impractical because the choppy sea in those locations was too rough for the small PBRs. Therefore, to accommodate the patrol boats the LST's were moved further up river, eventually as far as the Bassac-Mekong crossover (less than 20 nautical miles from the Cambodian border). The Navy also deemed it necessary to expand the two task groups into five groups in January 1968 and reassign them to individual rivers in the Delta region. The new groups and assignments included Task Group 116.1 to the
Bassac River, Task Group 116.2 to the
Mỹ Tho River Task Group 116.3
Upper Delta, Task Force 116.4
Co Chien River and Task Group 116.5 was assigned the Rung Sat area. ==Tet Offensive==