In May 1967, Vietnamese Army Intelligence reported four major Viet Cong bases in the Cam Son area of Dinh Tuong Province. The U.S. 2nd Brigade planned search and destroy operations to eliminate these bases using two battalions of infantry supported bytwenty-two ATC, two monitors and two CCB's of River Flotilla One.  A brigade command post and barge-mounted artillary were prepositioned near the operational area.  At 0815 hours on 15 May the 3rd Battalion landed at the mouth of the Rach Ba Rai.  Thirty minutes later Companies B and C 4th Battalion, 47th Infantry landed just west of the Rach Tra Tan. The troops moved inland and the boats took station to interdict possible enemy moves.  At 1200 hours Company A of the 4th Battalion, 47th Infantry was airlifted from Dong Tam base to a position 5 kilometers north of the My Tho River and west of the Rach Tra Tan.  At 1400 hours the two landing companies of the 4th Battalion, 47th Infantry - Companies B and C - made contact with a strong Viet Cong force and further progress became very difficult.  Company A was ordered to move south while the reconnaissance platoon of the 3rd/47th, held afloat, attempted to penetrate into the Rach Tra Tan to land on the enemy flank; it was driven by