The Patrol Craft Fast was a compromise wearing a uniform. Twin General Motors diesels drove it to 32 knots, which was its whole argument - fast enough to run down a junk, fast enough to leave. Two .50-calibre machine guns sat in a tub above the pilothouse, with an unusual over-and-under combination aft pairing another .50 with an 81mm mortar. The crew was six: an officer in charge, a boatswain's mate, a radarman-radioman, an engineman and two gunners, working within arm's reach of one another for days at a time. What the boat could not do was take a sea. Its shallow draft and low freeboard, ideal for oil-rig work in sheltered water, made it miserable and sometimes dangerous in open Gulf swell, and 193 of them were built anyway. Crews learned the boat's limits the way crews always do, at night, wet, and out of radio range.

The mission had a deceptively gentle name: Operation Market Time. Its object was to stop weapons reaching the Viet Cong by sea, and its method was to stop, board and search anything that floated. On 24 July 1965 the newly formed Division 11 of Coast Guard Squadron One left Subic Bay with nine Point-class cutters, escorted by the tank landing ship USS Floyd County, and reached An Thoi on 31 July. Patrols began the next day. The cutters normally carried eight men; the Coast Guard bumped that to ten for Vietnam to add seniority for boardings. Over the squadron's five years, the numbers became almost meaningless: more than four million miles cruised and 236,396 vessels boarded. Behind that second figure are Vietnamese and Khmer fishing families in wooden boats, hailed and searched again and again by armed strangers, most of them carrying nothing but fish - a daily indignity that never made the operational summaries.

An Thoi had begun as a Republic of Vietnam Navy post in the early 1960s, headquarters of Coastal District IV, renamed the 4th Naval Zone on 16 October 1963. There was almost nothing there. On 14 December 1964, engineers from the American construction consortium RMK-BRJ arrived aboard a motorised Vietnamese junk to fix that, and had an ocean pier finished by the end of April. In the meantime the Americans lived afloat: Floyd County served as repair shop and barracks until 17 September 1965, when the landing craft repair ship USS Krishna took over. Swift Boat crews slept aboard Krishna at first, then moved ashore into tents - and in tents they were shot at. In January 1966 RMK-BRJ started an airfield with a 4,000-foot asphalt runway, forty thousand square yards of pierced steel planking for an apron, a sea wall, barracks, two warehouses, another pier, a powerhouse, water and sewers. A war had built a small town.

The Americans left in stages rather than all at once. Division 11 was disestablished on 5 June 1969, its surviving cutters sent east to Cat Lo. The base itself was formally turned over to the Republic of Vietnam Navy on 28 May 1971, part of the vast transfer of hardware and responsibility that Washington called Vietnamization. After the last US forces went home, the RVNN's 4th Coastal Flotilla operated 26 patrol craft from An Thoi, covering the coast all the way down to the border of An Xuyen Province at the country's southern tip. It was an enormous stretch of water for a fleet that size, maintained by a navy running short of fuel and spare parts. In April 1975 the Republic of Vietnam ceased to exist, and the boats and the piers changed flags without a shot being fired at An Thoi.

The base never closed. It serves today as the Vietnam People's Navy's Region 5 command, still watching the same approaches, still tied to the same pier line. What changed is everything around it. Phu Quoc, Vietnam's largest island at 575 square kilometres, has turned into a resort economy of more than 150,000 residents, and in June 2025 it became the only city among the country's thirteen newly designated special administrative zones. A cable car now runs out over An Thoi township to the islet of Hon Thom, carrying holidaymakers over water where Swift Boats once idled at night with their engines down, listening. From a gondola you can look straight down and see grey hulls at their moorings: a working naval base beneath a queue for a beach club.