The Patrol Craft Fast (PCF),[7] also known as Swift Boat,[7] were all-aluminum, 50-foot (15 m) long, shallow-draft vessels operated by the United States Navy, initially to patrol the coastal areas and later for work in the interior waterways as part of the brown-water navy[8] to interdict Vietcong movement of arms and munitions, transport South Vietnamese forces and insert SEAL teams for counterinsurgency (COIN) operations during the Vietnam War.

Sewart Seacraft of Berwick, Louisiana (Swiftships' predecessor),[9][10] built water taxis for companies operating oil rigs in the Gulf of Mexico, which appeared nearly ideal.

The Navy bought their plans, and asked Sewart Seacraft to prepare modified drawings that included a gun tub, ammo lockers, bunks, and a small galley.

The original water taxi design had been enhanced with two .50 caliber M2 Browning machine guns in a turret above the pilot house, an over-and-under .50-caliber machine gun – 81 mm mortar combination mounted on the rear deck, a mortar ammunition box on the stern, improved habitability equipment such as bunks, a refrigerator and freezer, and a sink.

The most frequent training area for the Mare Island units was the marshland that forms the northern shoreline of San Francisco Bay.

[14] Here they patrolled the waterways and performed special operations, including gunfire support, troop insertion and evacuation, and raids into enemy territory.

Their missions included patrolling the waterways, searching water traffic for weapons and munitions, transporting South Vietnamese marine units and inserting Navy SEAL teams.

When the Swift Boats began making forays up the waterways into the interior of the delta, they initially took the carriers by surprise, causing them to drop their materials and run off into the overgrowth.

They set up ambushes, built obstructions in the canals to create choke points and began to place mines in the waterways.

Ambushes were typically short lived affairs, set up at a river bend or in a narrow canal that restricted the maneuverability of the boats.

[15] A wide variety of portable weapons were used in attacks, including recoilless rifles, B-40 rockets, .50 caliber machine guns and AK-47s, often fired from behind earthen bunkered positions.

[16] Engagements were brief and violent, with the ambushers often slipping away into the undergrowth when the boats located the source of attack and began to concentrate their return fire.

When attacked the boats would accelerate out of the hot zone, turn and then return as a group, firing as many of their guns as they could bring to bear.

The first report stated that four helicopters had been detected and were proceeding toward Tiger Island, just off the North Vietnamese coast at an altitude of 700–1,000 feet (210–300 m).

On this same evening the guided missile heavy cruiser USS Boston, operating near the DMZ, also began reporting helicopter activity in the vicinity of Bến Hải, Cap Lay and Tiger Island.

[22][21]: 240  The remaining crew managed to swim free from the sinking craft and cling to a life raft until USCGC Point Dume arrived on scene at 01:30.

As soon as the survivors were on board, Point Dume departed the scene to drop them off at the Cua Viet Base for a medevac to Danang.

When PCF-12 was 3 miles (4.8 km) from the river mouth, crewmembers observed two sets of aircraft lights off the port and starboard beam, about 300 yards (270 m) away and 100 feet (30 m) above the water.

PCF-12 came about, increased speed and moved away from the kill zone while bringing its .50-caliber guns to bear against an aerial target hovering at 1,000 feet (300 m) with lights blinking.

The crews of Point Dume and PCF-12 then observed numerous lighted aircraft that appeared to be helicopters in the northern part of the area.

[21]: 241 On the afternoon of 16 June, Task Unit 77.1.0 ordered USS Edson, USS Theodore E. Chandler and the Royal Australian Navy guided-missile destroyer Hobart HMAS Hobart to conduct a surveillance mission in the vicinity of Tiger Island in attempt to flush out any enemy helicopters or waterborne craft operating from there.

At 01:18 on the 17th, Boston, which was engaged in a naval gunfire support mission in the same general area, came under attack from an unidentified jet aircraft.

At 03:09, while Hobart was searching a 5-mile radius area between the coast and Tiger Island with its radar, it detected a single aircraft tracking east.

Later research of the incident with surviving veterans and a review of salvage reports from USS Acme, the ship that recovered the bodies and codebooks from PCF-19 shortly after the attack, found that the rocket entry holes in the hull of PCF-19 were 76.2mm in size—the size of a standard helicopter rocket carried by a Soviet-manufactured Mi-4 Hound helicopter and not Sparrow or Sidewinder holes, which would have been larger.

[33] One of the two patrol boats headed back to the United States to become a memorial in summer 2012 at the Maritime Museum of San Diego in California.

[34] The museum has a display paying tribute to the Maltese servicemen who died on board the P23 (the sister vessel of P24) during an accident that occurred on September 7, 1984.

The incident – known as the C23 tragedy and the worst peace-time accident suffered by Maltese services personnel – killed five AFM soldiers and two policemen when illegal fireworks about to be dumped into the sea exploded on the bow of the small patrol boat.

Senator Bob Kerrey, a recipient of the Medal of Honor,[39] and Arizona Congressman Jim Kolbe, who served in the United States Navy.

As the Democratic nominee for president in 2004, then-Senator Kerry's military record was attacked by a political 527 group called Swift Boat Veterans for Truth.

In an article in The New York Times on June 30, 2008, Swift Boat veterans objected to the prevalent use of the verb "swiftboating" as this type of ad hominem attack, stating that it is disrespectful to the men who served and died on the PCFs during Vietnam.