RIVERINE ASSAULT FORCE SUMMARY
Naval units of the Mobile Riverine Force participated in operations which were characteristically diversified as to type of mission and area of employment during April. Reconnaissance in force, search and destroy, patrol, ambush, troop lift, inspection, Eagle Float, fire support, blocking force, escort and psyops duties were carried out by river assault craft often in conjunction with U.S. Army or Vietnamese forces as they operated from the GIANT SLINGSHOT Campaign area (the northern most area of Navy involvement in the Delta region) to the southern most reaches of the Cau Mau Peninsula (SILVER MACE II Campaign). The long term riverine assault operations in Kien Hoa Province continued as the combined Army/Navy units again inflicted severe losses on the enemy.
The following table indicates the distribution and employment of river assault craft on a typical day in April:
MRF CRAFT ASSIGNED
ASPB ATC MON CCB REFUELER TOTALS
2nd Brigade, U.S. 9th
Infantry Division 12 36 9 5 1 63
Operation GIANT SLING-
SHOT/Barrier Reef 16 21 3 2 1 43
Operation SILVER MACE II 4 17 5 2 1 29
Base Defense 6 15 1 22
Overhaul/Conversion/Backfit 2 2 4
TOTALS 40 91 17 9 4 161
Downgraded at 3 year intervals
Declassified after 12 years
The recurring danger of enemy swimmer/sapper activity against river craft was in evidence again this month as three mining incidents or attempts were recorded against MRF craft operating in Kien Hoa Province and enemy Base Area 480. On 22 April, while transiting enemy Base Area 480 enroute to the MRB after completion of Operation SILVER MACE II, RAD 132 assault craft were engaged in an enemy initiated firefight on the Song Cai Tu 8 1/2 miles southwest of Vi Thanh (WR 420 756). During the action a watermine exploded 60 feet off the starboard bow of CCB-132-1 and caused minor flooding which was brought under control. Potential disaster was averted on 24 April when a Viet Cong command detonated mine was discovered attached to the anti-swimmer net of APL-26 between the bow and pontoon. The homemade mine, weighing approximately 150-175 pounds, was discovered at 0730. Fish floats were seen attached to the barrier while it was being raised prior to getting underway; inspection by EOD personnel revealed the mine with the detonator lead severed. Speculation was that the detonator wire was cut during a minesweep patrol by a base defense boat. Lastly, ASPB 132-3 was sunk on 29 April on the Cai Tu River as an enemy mine of unknown type was detonated beneath its stern during the operation in enemy Base Area 480 in Chuong Thien Province. A second ASPB, 132-1 was damaged as a result of the explosion. (This incident is described in the SEA LORDS section under Operations in Enemy Base Area 480.) The sunken ASPB was already hauled up on a beach by April 30 as the timely salvage operations continued.
This is ASPB 132-3 at Dong Tam
Salvage operations on Monitor 111-1 which was sunk as a result of battle damage on the Vam Co Tay River, 4 1/2 miles northeast of Moc Hoa were completed on 20 April and the craft was towed to Nha Be. The extensive repairs necessary are estimated to require use of out of country facilities. The monitor had sunk on 31 March.
River Assault Division 92 commenced six days of training for Vietnamese Navy boat crews on 28 April under the Accelerated Turnover Program (ACTOV). This training is in connection with a scheduled incremental turnover of RAC to the VNN in June.
Loudspeaker psyops broadcasts were an important aspect of RAC activity as tapes were played in all operating areas, at times during insertion/extraction of troops and immediately after firefights.
TASK GROUP 117.1 Operations
The concerted efforts of the MRF in Kien Hoa Province and adjacent areas again resulted in a record number of enemy casualties as aggressive search and destroy tactics accounted for 1155 Viet Cong killed during April. Side thrusts of a few days duration were also made by MRF forces into Go Cong and Vinh Binh Provinces during the month.
Enemy initiated activity during April diminished somewhat as hostile fire incidents directed against TG 117.1 RAC were encountered on eight occasions as compared to 21 such incidents last month. U.S. Navy casualties during these actions were 27 wounded.
River assault craft of River Assault Divisions (RAD) 131, 132, and
151 supported the 3/47th, 4/47th, 3/60th and 6/31st Infantry battalions of the U.S. Army Ninth Infantry Division at various times throughout the month as assault landings were conducted along numerous rivers and canals throughout the operating area. RAD 92 as utility division provided frequent escort services, supported the 3/34th Artillery Battalion at fire support bases and commenced ACTOV training with the VNN. RAD 152 acted as base defense division. On 25 April RAD 131 relieved RAD 111 in the GIANT SLINGSHOT area.
On 2 April, nine RAC of RAD 131 (with one company each of 4/47th & 3/60 infantry and the headquarters company of 3/34 Artillery embarked) were engaged in an enemy initiated firefight on the Rach Mo Cay, 13 miles south of My Tho (XS 468 206) while escorting 3/34th artillery barges. About eight B-40 rockets and heavy automatic weapons were fired at the boats resulting in one rocket hit each on Monitor 151-1 and ATC 131-12 and minor material damage. Fire was immediately returned and suppressed by the boat column and LHFT overhead. Nine Navymen were wounded (all minor); one soldier was killed and four were wounded in the attack. Enemy casualties were one killed with other results of suppressive fire unknown.
Seven RAD 92 units, engaged primarily in fire support base (FSB) security operations during April, were enroute on 16 April from the mobile riverine base at Dong Tam to FSB Khan when they received five recoilless rifle rounds from the south bank of the Song Ben Tre, 8 miles southeast of My Tho (XS 532 313) at 0935. Monitor 92-1 and Refueler 112-1 were
hit by one round each wounding three sailors. All units returned and suppressed the fire. The refueler was carrying Mogas in the well-deck; this was ignited and the boat became engulfed in flames. The blazing boat was immediately beached and the crew evacuated to ATC's 92-7 and 93-3. Firing commenced immediately and was aided by the quick arrival of additional equipment and firefighting foam flown to the scene by an Army helo. The fire was extinguished at 1115. An Army LHFT came on station immediately and Army 1st Air Cavalry troops arrived within 10 minutes to provide security for salvage operations. The boat was towed to Dong Tam for repairs.
This is the Refueler mentioned above.
On 26 April ATC's 152-7 and 152-13, while on base defense patrol, sighted a total of five persons at two locations on the south bank of the My Tho River (XS 383 406 and XS 400 407) two miles southwest of Dong Tam. The Viet Cong were spotted in a free fire zone with a night observation device. The RAC took the Viet Cong under fire resulting in two probable kills.