Her tasking during the conflict was primarily in support of Operation Market Time, which involved sorting through hundreds of small vessels off the Vietnamese coast in search of enemy weapons smugglers.

The old 5" gun (now replaced by a 76mm mount) answered 152 calls for naval gunfire support, including a running fight on the night of 21 November 1970 which resulted in sinking the North Vietnamese armed freighter SL-3, which was carrying tons of enemy munitions.

Sherman's primary missions shifted to Alaskan Patrols (ALPAT) involving fisheries law enforcement (LE), drug interdiction, search and rescue (SAR), and military readiness in the Bering Sea and Gulf of Alaska.

[1] In July 2001, Sherman became the first Coast Guard cutter to circumnavigate the world, after conducting U.N. sanctions enforcement duty in the Persian Gulf and goodwill projects in Madagascar, South Africa, and Cape Verde.

In March 2007, Sherman received worldwide attention when her boarding team discovered more than 17 metric tons of cocaine aboard the Panamanian freighter Gatun, a record seizure in the Eastern Pacific.

The ship retained its Otobreda 76 mm gun and MK 92 Fire Control System, while the Phalanx CIWS was removed and was replaced with a rear mounted dual 23mm cannon.

Departing from the Colombo harbour and sailed within Sri Lankan territorial waters allowing President Rajapaksa to maintain communications while being safely out of reach of the protesters.