This Day in Coast Guard History – March 12
1955- Effective this date, all foreign and domestic ships were required to give 24-hour advance notice to the local U.S. Coast Guard Captain of the Port before entering U.S. ports. This order was designed to improve the U.S. Coast Guard's port security program without "material inconvenience" to shipping.
1965- This date marked the beginning of the US Navy’s Operation Market Time to interdict the river and coastal water supply lines of Communist forces in South Vietnam. The initiation of this campaign led to the Navy’s request for Coast Guard vessels and crews to participate in river and coastal patrols during the Vietnam War.
(Source: USCG Historian’s Office)