The Action Of 1 March 1968 refers to a co-ordinated attempt by four North Vietnamese trawlers to resupply the Viet Cong and the efforts of Operation Market Time elements to stop them during the Vietnam War. On 28 February 1968, United States Navy SP-2H Neptune aircraft on routine patrol detected a North Vietnamese SL class naval trawler heading towards the South Vietnamese coast from north of the DMZ. By the next morning, three more trawlers were discovered and units of Operation Market Time were deployed for a surprise interception. The suspect trawlers did not fly flags so it was not until the start of the engagement that their origin was discovered. The trawlers were steel hulled vessels, 100 feet long and armed with 57-millimeter recoilless rifles and machine guns. All four vessels wer