From Naval History and Heritage Command
Most of the blogs that appear on this space are tributes to the Blue Water Navy, those Sailors and Marines who fought their enemies in magnificent warships, impenetrable ironclads, stealthy submarines and a whole fleet of aircraft carriers, cruisers, destroyers and their flying machines.
Not this blog. This blog is a tribute to the Coastal Surveillance Force that produced some of the greatest naval successes during the Vietnam War, the black beret-wearing Sailors of the Brown Water Navy.
Communists, coastlines and Viet Cong
When the Geneva Accords divided Vietnam into South and North, it provided a loophole that gave Communist leader Ho Chi Minh’s supporters an edge: A period of free movement between the two countries. With thousands of his supporters left in the South, Ho Chi Minh recruited thousands more to bring to the north and train for later insertion.
As a result, the communist-led National Liberation Front had a ready army of Viet Cong in the heavily-infiltrated provinces along the Mekong Delta. Since the Vietnamese army and navy were outnumbered, they rarely patrolled the rivers and coastline to stop clandestine movement of supplies to the Viet Cong. At the time, the U.S. Navy patrolled mostly in the deeper waters, with helicopters and patrol planes providing surveillance for American and Vietnamese ground troops.
It was Feb. 16, 1965, when Army Huey pilot Lt. James Bowers flew over the South China Sea near the Vietnamese coastal village of Vung Ro and saw something that didn’t look right. An island seemed to be moving. As he moved in for a closer inspection, the “island” fired back. It was a trawler covered with plants around its frame and deck, filled with a boatload of weapons and ammunition headed toward the Viet Cong.
After capturing the trawler, the U.S. Military Assistance Command Vietnam decided to stop the supply route to the Viet Cong. It was PBR-time, and by PBR we don’t mean beer, but rather Navy nomenclature for “patrol boat, river.” Navy leadership quickly created task forces of river patrol boat squadrons, some in partnership with the U.S. Coast Guard.
So it was on March 11, 1965, 49 years ago today, that Task Force 115 stood up, the Coastal Surveillance Force. Made up of three squadrons — two Navy and one Coast Guard – it conducted operations under the code name Market Time.
It’s Market Time for river patrol boats
While the Navy had plenty of deep water ships in the area, what they needed were quick and agile boats. At first, they borrowed ships from the Coast Guard, cutters and river patrol boats pimped out for combat with .50-caliber machine gun and 81-mm mortars installed on the forecastle and four .50-caliber deck guns on the fantail.
But even more agile boats were necessary, and for that, the Navy turned to Sewart Seacraft of Burwick, La., purchasing more than 100 fast patrol boats (PBF). The “Swift” boats drafted but 3 ½ feet, powered by two diesel engines with twin screws and speedy at 28 knots. For armament, they sported twin .50-caliber machine guns forward and a .50-caliber machine gun/81 mm mortar combination aft.
The operation was named Market Time as a reference to commercial and marketing ships that would ultimately fall under their jurisdiction. All were suspect. When they weren’t stopping, boarding and inspecting ships that ranged from trawlers to fishing boats, the crews provided naval gunfire support for troops on shore, transporting troops and evacuating civilians and providing medical outreach to the communities. They also put in aids to navigation for unchartered waters.
The squadrons used a variety of boats and ships, from destroyers and minesweepers that patrolled in deeper water to shallow water vessels like fast patrol craft, Coast Guard cutters, gunboats and even air cushioned patrol vehicles. More backup came from observation aircraft like P-2 Neptunes and P-3 Orions in international waters. The area of responsibility stretched across approximately 1,200 miles of coastline from Da Nang in the north to Phu Quoc Island in the south, and 40 miles out to international waters
Within a year, Operation Market Time virtually halted the Viet Cong’s resupply line from the north. For example, the seven-day detailed reports showed a steady decline in the number of ships detained for contraband. From April to May, 1966, the numbers reflected 18 junks detained along with 110 people after searching 4,686 vessels and 18,446 people, to detaining only two junks and 99 people while searching 5,340 vessels and 21,543 people.
That forced the Communists to find other ways of supplying the Viet Cong, sending them inland by way of the Ho Chi Minh Trail and through Laos and Cambodia.
After the Tet Offensive in January 1968, when the Viet Cong executed a series of attacks throughout South Vietnam, Ho Chi Minh was desperate to replenish his troops in the south, and so he looked again toward his fastest route of delivering supplies. During the evening of Feb. 29, 1968, four separate attempts were made by Communist ships to slip through the blockades. That day would end up as the largest naval battle during Vietnam, based on numbers of ships and scope of territory.
Coastal Surveillance Force 4, Viet Cong 0
It started south of Da Nang as a 100-foot-long trawler ignored warning shots by the Coast Guard cutter Androscoggin. The trawler returned fire and the battle began, with the cutter joined by two other cutters and helicopter gunships. Trapped, the trawler’s captain headed for shore, beaching his ship. At 2:35 a.m., the trawler exploded.
The second battle was at nearly the same time, off the Ca Mau peninsula, when another Communist trawler tried to breach the inner barrier. Four cutters came to attack, supported by Navy Swift boats. Overwhelmed with U.S. gunfire, the trawler burst into flames and exploded.
Northeast of Nha Trang, another trawler was caught in the inner barrier by a force of Swift boats, Vietnamese junks, Vietnamese Navy, Fleet Command ships and an AC-47 aircraft. The trawler’s captain ran the ship onto the beach, destroying it, but the supplies were salvaged, a boatload of automatic rifles, rocket launchers, rocket rounds, 82mm mortar tubes with hundreds of rounds of ammunition and more than two dozen cases of 7.62mm ammunition.
The captain of the fourth trawler decided to cut his losses and returned back to North Vietnamese waters after the Coast Guard cutter Minnetonka intercepted him in the international waters near the border.
After that night of four engagements and failed missions, the North Vietnamese never made another such maneuver to resupply their troops by sea.
BZs for Brown Water Navy
The success of Market Time interdiction operations was considered one of the great successes of the Vietnam War, as noted in a “lessons learned” study commissioned by the Department of the Army.
“Operation Market Time has been judged to have produced significant results and is credited with forcing the enemy to change his logistic operations extensively. In early 1966, it was estimated that the enemy accomplished three-quarters of his resupply by infiltration from the sea. By the end of 1966, this was reduced to an estimated one-tenth of the total resupply.”
Army Gen. William Westmorland praised the work performed by the Brown Water Navy as well: “Market Time forces have successfully blocked intrusions by sea, forcing the enemy to use the long, torturous Ho Chi Minh Trail, thus affecting significantly his ability to properly sustain his forces in the South.”
Information for this blog came from previous articles from Naval History and Heritage Command and a 2008 report The Brown Water Navy in the Mekong Delta: COIN in the Littorals and Inland Waters by Lt. Cmdr. Richard E. Sessoms.