Hawaiian area operations

After conducting minesweeping operations in the Pearl Harbor channel and other Hawaiian waters, Vireo underwent upkeep at Pearl Harbor between 10 and 13 February 1942. Following local operations near Honolulu and Pearl Harbor, she made brief runs to Johnston Island and the port of Hilo.

In April and May 1942, after another brief stretch around Pearl Harbor, Vireo conducted local patrols out of Hilo, sometimes in company with USS Crossbill (AMc-9) to conduct magnetic, acoustic, and mechanical minesweeping operations; and to patrol harbors with her echo-ranging and listening gear. From 23 to 24 April, Vireo, in company with Crossbill and USS Sacramento (PG-19), conducted a search for survivors of a downed Army plane off Pepeekeo Point, near Hilo, and found one body before she abandoned the task.

The Battle of Midway

Air action the following day, 4 June 1942, was intense. Japanese carriers Akagi, Kaga, Soryu, and Hiryu were all crippled and sunk by American planes. However, American carrier USS Yorktown (CV-5) became the unfortunate victim of Japanese dive and torpedo bombers which heavily damaged the carrier, stopping her dead in the water, and forcing a severe list.

Vireo takes Yorktown in tow

Lest the ship capsize before the crew could be removed, Capt. Elliott Buckmaster ordered Yorktown abandoned. When Yorktown stopped settling, Buckmaster concluded that the ship could possibly be saved. Accordingly, Vireo received a summons to take Yorktown in tow. The tug arrived on the scene by 1135 on 5 June and closed and maneuvered to pass Yorktown a towline, accomplishing this by 1308. Vireo and her unwieldy charge then labored painfully ahead, at a speed of under 3 knots, with a protective brood of destroyers standing by.

Vireo, hampered by a small rudder and inadequate engines for such a large tow, found herself confronted with the Herculean task of keeping the big carrier pointed into the wind and on course. The next day, USS Hammann (DD-412) secured alongside Yorktown to assist the salvage parties on the larger ship working to correct her trim and to repair her battle damage.

Around 1400 on 6 June, Japanese submarine I-168 fired torpedoes at the nearly helpless targets. Hammann, mortally hit, broke in two and sank alongside the towering carrier, which also took two torpedoes. As the destroyer sank, her depth charges all went off at once, causing tremendous shock waves which convulsed swimmers in the water and violently wrenched the old tug. Vireo freed herself from the carrier by cutting the towing cable with an acetylene torch and then doubled back to commence rescue operations.

Up her sides clambered carriermen and destroyermen alike, while she maneuvered near the carrier's canting stern to take on board members of the salvage party who had chosen to abandon the carrier from there. She then proceeded to secure alongside the wounded flattop in the exact spot where Hammann had met her doom. Yorktown rolled heavily, her heavy steel hide pounding the lighter former minecraft's hull with a vengeance as the ships touched time and time again during the rescue operations. This mission completed, battered Vireo stood away from the sinking carrier, which sank shortly after dawn on the 7th.

Vireo's troubles, however, had only begun. Underwater explosions from Hammann's depth charges had severely jostled the tug's rudder. As a result, it jammed as Vireo was entering the shipping channel at Midway harbor on 8 June, and she ran aground on a coral head, carrying away her echo-ranging gear and flooding her sound room. Repeated attempts to free herself only resulted in another grounding, so Vireo lay-to and called for a tow.

After arriving at Midway Island at the end of a towline from YMT-12, following another brush with a coral head which irreparably damaged the rudder, Vireo soon got underway for Pearl Harbor, this time behind USS Seminole (AT-65). Reaching Hawaiian waters on 17 June, she entered the navy yard at Pearl Harbor for emergency repairs which lasted from 18 to 30 June. Following this, she remained at the Pearl Harbor yard for a complete overhaul and drydocking.

Converted into a tow ship and sent to Fiji

Vireo (AT-144) at Pearl Harbor, 20 August 1942.

Having concluded the refitting by 19 August, Vireo conducted post-repair trials before turning in all her mine gear on 25 August. Two days later, she got underway to escort SS Gulf Queen to the Fiji Islands, towing two barges. Upon her arrival at Suva on 11 September, the tug refueled, provisioned, and carried out minor repairs before heading for New Caledonia on 15 September. After arriving at Noumea five days later, on 20 September 1942, she commenced harbor operations under the control of Commander, Amphibious Forces, South Pacific (AmphibForSoPac). In accordance with verbal orders from ComAmphibForSoPac, Vireo's crew set about making camouflage nets and painting the ship green in preparation for her next assignment.

Guadalcanal operations

Arriving at Espiritu Santo on 8 October, she awaited further orders, spending four days at this port in the New Hebrides before setting out for the Guadalcanal area on 12 October, to take part in resupply operations for the U.S. Marines at Henderson Field.

Since the initial landings on Guadalcanal on 7 August 1942, the campaign had been fought tooth and nail. Fierce land and sea battles had characterized the fighting since the early going. By this juncture, American aviation operations on Henderson Field had been so endangered by shellings, bad weather, and inadequate supplies, that the American situation was extreme.

With American aircraft using up gasoline at an alarming rate, that commodity ranked high on the list of priority supplies. Accordingly, a barge-towing operation was mounted in mid-October to ease the critical fuel situation on Guadalcanal.

The force to carry out this operation comprised USS Alchiba (AK-23), USS Bellatrix (AK-20), USS Jamestown (PG-55), USS Meredith (DD-434), USS Nicholas (DD-449), and Vireo, each pulling a barge carrying barrels of gasoline and quarter-ton bombs. Setting out from Espiritu Santo, the highly volatile convoy was spotted by Japanese aircraft on 15 October. All but Vireo and Meredith beat a hasty retreat.

Cautiously proceeding, the pair beat off a two-plane Japanese attack before they received word that Japanese surface ships were in the area. Only then did they reverse course. At noon, Meredith ordered old, slow, and vulnerable Vireo abandoned and took off her crew. Meredith then stood off to torpedo the tug at 1215 so that she would not fall into enemy hands intact. Suddenly, a whirlwind of destruction swept down from the sky and descended upon the destroyer. Like hawks, 38 planes from the Japanese carrier Zuikaku pounced on Meredith and deluged her with bombs, torpedoes, and bullets, sinking her in about 15 minutes.

Vireo and the two gasoline barges, however, drifted to leeward, untouched. One life raft, crammed with some of Meredith's survivors, succeeded in intercepting the derelict tug and the men gratefully scrambled aboard. The barges and the tug were later found intact by a PBY naval scout plane which rescued six of the Meredith's crew. When a salvage party boarded Vireo on 21 October, the ship was dead in the water with no lights, no steam, and no power. After abortive attempts to light fires under the boilers, using wood, the tug had to be taken under tow by USS Grayson (DD-435). In company with Grayson and USS Gwin (DD-433), Vireo arrived safely at Espiritu Santo on 23 October.

With a new crew—the majority of her old complement lost in the ordeal with Meredith—she continued to operate in the Guadalcanal area with Task Force 62. She conducted resupply operations to Guadalcanal, towing barges loaded with precious gasoline and bombs and carrying out local escort for other, larger ships, engaged in the same vital duties.

On 3 December, in company with USS Hilo (AGP-2) and towing PT boats, she departed Nouméa and proceeded to Australia. Arriving at Cairns on 9 December, she spent the remainder of the year there, enjoying Christmas and New Year's Day in Australian waters before heading back to the combat area, arriving at Espiritu Santo on 9 January.

Return to Guadalcanal operations

Operating out of the New Hebrides in early January, she assisted cruisers USS Pensacola (CA-24) and USS Minneapolis (CA-36) as they underwent repairs following damage received at Tassafaronga. Towing barges and firing target bursts for destroyers during gunnery practice off Guadalcanal, the tug continued her operations as before, between that island and Espiritu Santo and Nouméa. It was dull and monotonous duty but necessary and vital, nonetheless.

In April 1943, as American forces advanced on the "island-hopping", "leap-frogging" campaigns against the Japanese in the South Pacific, Japanese Admiral Yamamoto initiated operation "I." Yamamoto aimed this stroke at Papua, in the hope of compensating for the loss of Guadalcanal, by destroying the American advance base there and thus slowing or stopping the Allied advance. The new Japanese thrust began on 7 April when large formations of Japanese planes swept down from Rabaul to attack American shipping in Lunga Roads between Guadalcanal and Tulagi.

Among these ships, there lay Vireo, engaged in her usual harbor activities. Pathfinder was engaged in taking soundings; also near were USS Ortolan (ASR-5) and SC-521. Shortly before the attack came, USS Aaron Ward (DD-483) passed by, escorting LST-U9. Three Japanese dive bombers swooped down out of the sun and severely damaged the destroyer with their lethal loads. Ortolan and Vireo took the crippled Aaron Ward under tow, but the destroyer sank three miles short of Tulagi.

The Battle of Kula Gulf

As the New Georgia campaign got underway and American forces advanced further up the chain of islands in the southwest Pacific, Vireo continued her operations out of Tulagi, Espiritu Santo, or Nouméa. In the pre-dawn darkness of 13 July, the Battle of Kula Gulf was fought between Japanese and American surface forces, the latter augmented by New Zealand cruiser Leander. In the action which followed, USS Honolulu (CL-48), USS St. Louis (CL-49), and Leander were damaged. Later that day, Vireo, in company with USS Rail (AT-139) set out to assist in getting the cripples home and towed Honolulu to haven at government wharf, Tulagi, where temporary repairs to the cruiser's bow were made.

Supporting the Philippine invasion

After service in the South Pacific Ocean, the old tug moved northward with the invasion armada to liberate the Philippine Islands from the Japanese. On 18 October 1944, American troops stormed ashore on Leyte, keeping General Mac Arthur's promise to return to Philippine soil. Vireo operated in support of these landings into December. She departed Morotai on the 10th, bound for Biak. From there, she proceeded to Leyte, engaged in towing duties.

Supporting Okinawa invasion

Next—after touching at Hollandia, Manus, and Biak—she took part in the Okinawa operations in April and May 1945. Returning to Morotai, she engaged in towing operations again, this time to Tacloban on the island of Leyte, departing there on 25 May for Subic Bay. For the remainder of the war, she operated between the Philippine Islands and New Guinea, as American forces continued to sweep northward towards the Japanese home islands.

End-of-war operations

On 20 December 1945, after immediate postwar towing operations at Manila, Luzon, and Samar, she departed Philippine waters on 20 December 1945, in company with USS Rail (ATO-139) and USS Whippoorwill (ATO-169), and headed for the Marshalls.

Following a brief stay at Eniwetok, Vireo got underway on 4 January 1946 and proceeded via Pearl Harbor to the west coast. She arrived at San Francisco, California, on 5 February and reported to the Commandant, 12th Naval District, for disposition.