On 28 February 1965, the ammunition ship arrived at the Lockheed Shipbuilding and Construction Company yards, Seattle, Washington.
There having reverted to in commission in Reserve status, Mauna Kea commenced FAST (Fast Automatic Shuttle Transfer System) conversion.
Completion of this conversion, which would enable her to transfer a missile from her hold to the magazine of a missile‑firing ship in 90 seconds and allow her greater versatility in servicing the fleet with the addition of a helipad for vertical replenishment capabilities, was delayed for 8 months, because of strikes and lack of necessary parts, until June 1966.
Then followed a fitting out period and intensive post-conversion shakedown exercises, which continued into the fall.
By November she was again an active unit of the Pacific Fleet’s Service Force and on 28 December she departed her home port of Concord, California, for her ninth WestPac deployment.

Traveling westward, Mauna Kea arrived at Subic Bay, Philippines, 9 January 1967 to join ServRon 7.
Four days later she departed Subic Bay for her first trip to the line off Vietnam.
For the next six months she rearmed carrier groups on Yankee Station and cruisers and destroyers off South Vietnam.
At the end of July, she headed north to Japan for a brief visit at Yokosuka before getting underway for California.
Arriving at Concord, 22 August, she underwent availability and then commenced participation in fleet and local exercises along the California coast.

On 20 February 1968, Mauna Kea departed the Naval Weapons Station, Mare Island Annex, Vallejo, California for a WESTPAC deployment.
Mauna Kea performed munitions underway replenishment (UNREP) operations to units of the 7th Fleet in the South China Sea and Gulf of Tonkin off the coast of South Vietnam.
With the exception of UNREP operations at Subic Bay and a port visit to Hong Kong, Mauna Kea conducted these operations in direct support of combat operations from 14 March 1968 to 25 September 1968.
During the period of 15 to 16 May 1968, Mauna Kea anchored at Anchorage #13 in Da Nang Harbor, with no disposition.
On 17 May 1968, the USS Mauna Kea departed the Gulf of Tonkin en route to Subic Bay, arriving 18 May 1968.
The ship visited Hong Kong during the period of 10 June to 15 June 1968.
Mauna Kea departed Yankee Station on 26 September to return to her homeport, Concord, California, arriving on 14 October 1968.

Afterwards she, through the end of 1970, continued servicing the 1st Fleet until setting out for the western Pacific and another tour with the 7th Fleet.
On 28 February 1965, the ammunition ship arrived at the Lockheed Shipbuilding and Construction Company yards, Seattle, Washington. There having reverted to in commission in Reserve status, Mauna Kea commenced FAST (Fast Automatic Shuttle Transfer System) conversion. Completion of this conversion, which would enable her to transfer a missile from her hold to the magazine of a missile‑firing ship in 90 seconds and allow her greater versatility in servicing the fleet with the addition of a helipad for vertical replenishment capabilities, was delayed for 8 months, because of strikes and lack of necessary parts, until June 1966. Then followed a fitting out period and intensive post-conversion shakedown exercises, which continued into the fall. By November she was again an active unit of the Pacific Fleet’s Service Force and on 28 December she departed her home port of Concord, California, for her ninth WestPac deployment.
Traveling westward, Mauna Kea arrived at Subic Bay, Philippines, 9 January 1967 to join ServRon 7. Four days later she departed Subic Bay for her first trip to the line off Vietnam. For the next six months she rearmed carrier groups on Yankee Station and cruisers and destroyers off South Vietnam. At the end of July, she headed north to Japan for a brief visit at Yokosuka before getting underway for California. Arriving at Concord, 22 August, she underwent availability and then commenced participation in fleet and local exercises along the California coast. 
On 20 February 1968, Mauna Kea departed the Naval Weapons Station, Mare Island Annex, Vallejo, California for a WESTPAC deployment. Mauna Kea performed munitions underway replenishment (UNREP) operations to units of the 7th Fleet in the South China Sea and Gulf of Tonkin off the coast of South Vietnam. With the exception of UNREP operations at Subic Bay and a port visit to Hong Kong, Mauna Kea conducted these operations in direct support of combat operations from 14 March 1968 to 25 September 1968. During the period of 15 to 16 May 1968, Mauna Kea anchored at Anchorage #13 in Da Nang Harbor, with no disposition. On 17 May 1968, the USS Mauna Kea departed the Gulf of Tonkin en route to Subic Bay, arriving 18 May 1968. The ship visited Hong Kong during the period of 10 June to 15 June 1968. Mauna Kea departed Yankee Station on 26 September to return to her homeport, Concord, California, arriving on 14 October 1968.
Afterwards she, through the end of 1970, continued servicing the 1st Fleet until setting out for the western Pacific and another tour with the 7th Fleet.
USS Mauna Kea (AE-22)