USCGC Klamath (WHEC-66) was an Owasco-class high endurance cutter built for World War II service with the United States Coast Guard.

Her ID was later changed to WHEC-66 (HEC for "High Endurance Cutter" - the "W" signifies a Coast Guard vessel).

January 1972, Klamath was dispatched from Alaskan patrol to render assistance to the Japanese freighter Tenzan Maru, which was taking on water 800 miles west of Seattle.

Klamath crew boarded the Tenzan Maru and installed temporary repairs, then escorted the freighter to San Francisco.

In February 1972, a boarding party from Klamath helped save the badly damaged MV Tenzan Maru and she was subsequently escorted to safety.