Which US Navy operation tried to stop communist supplies reaching South Vietnam by sea?

Which US Navy operation tried to stop communist supplies reaching South Vietnam by sea? Operation Market Time.

Launched in 1965, Operation Market Time was a maritime interdiction campaign intended to block North Vietnamese ships carrying troops, weapons, and supplies to communist forces in South Vietnam. It covered coastal waters, river mouths, and approaches used by supply trawlers.

The operation combined US Navy ships, US Coast Guard cutters, Republic of Vietnam Navy vessels, aircraft, and Royal Australian Navy support. Patrol Craft Fast boats, commonly called Swift boats, inspected coastal traffic, while larger ships and aircraft watched for disguised trawlers. The campaign followed the discovery of a major weapons shipment at Vũng Rô Bay in February 1965.

Market Time is often confused with bombing campaigns such as Rolling Thunder or with river operations conducted under Operation Game Warden. Its focus was maritime supply movement rather than strategic bombing. The blockade sharply reduced successful seaborne infiltration, although it could not stop the extensive overland supply network associated with the Ho Chi Minh trail.