Two additional permanent Marine advisor billets were also approved in the closing weeks of 1964. These were created within the Naval Advisory Group to assist the Vietnamese Navy in controlling one of South Vietnam’s most troublesome areas--the Rung Sat Special Zone (RSSZ). Located southeast of Saigon on both sides of the Long Tao River, the main ship channel to the capital, the Rung Sat was a vast, difficult-to-penetrate, mangrove swamp. Due largely to its relative inaccessibility, the area had been developed by the Viet Cong into a key base for supporting their operations in the surrounding provinces. More significantly, by early 1964 the Communist-held Rung Sat posed a serious threat to commercial ships bound for Saigon. For this reason the responsibility for pacifying the area was turned over to the Vietnamese Navy in April. Initially one Marine major, Edward J. Bronars, was assigned to assist and advise the Vietnamese Navy in its attempts to secure the Rung Sat. In November, however, the RSSZ advisory staff was reorganized to include one Marine captain and one sergeant. Although they did not arrive for duty until early the following year, the newly approved billets created the third distinct group of Marine ground advisors assigned to the Republic of Vietnam.[10-10] The OJT program continued in effect for junior Marine officers and staff noncommissioned officers throughout 1964. Near the end of the year the program was broadened somewhat to include members of Hawaii-based Marine commands. Each month 10 Leathernecks arrived at Da Nang to begin their 30-day assignments. At SHUFLY headquarters the visitors were briefed as a group before being attached individually to specific South Vietnamese units for the duration of their stay in Vietnam. Normally, the officers and staff noncommissioned officers joined a unit already being advised by a U.S. Marine. When possible, the OJT was assigned to a unit which could benefit from his particular military and technical skills. Still, the on-the-job-trainee was not always considered an asset. “In honesty,” one permanent advisor to the Vietnamese Marine Corps conceded, “OJTs were a mixed blessing--they provided some help but they also were an added responsibility for the VNMC commander who was charged with their safety.” “Some OJTs,” he added, “received misperceptions of the capability of the Viet Cong since their knowledge/experience was limited to the events occurring during their brief 30-day tour.”[10-11] Nevertheless, a significant number of Marine small unit leaders were able to gain some degree of first-hand experience in counter guerrilla warfare under the provisions on the OJT program.[10-I]