She was attached to the Atlantic fleet and served along the east coast and in the West Indies until spring of 1914 when she was dispatched along with other ships for the occupation of the Mexican port of Vera Cruz.

The auxiliary vessel provided repair services at Vera Cruz from 2 May to 20 September before she sailed for Boston, escorting the cruiser Salem to the navy yard there for overhaul.

After returning from the west coast for an overhaul at the Mare Island Navy Yard, Vallejo, California, Vestal resumed her duties.

One struck the port side, penetrated three decks, passed through a crew's space, and exploded in a storage hold, starting fires that necessitated flooding the forward magazines.

The resultant explosion touched off adjacent main battery magazines, exploding the forward part of the battleship and literally clearing Vestal's deck of her crew.

Within a week of the raid Vestal's crew had pumped out the oil and water that had flooded the compartments below the waterline and cleared out the damaged and gutted holds – all work that had to be completed before the rebuilding process could begin.

With only six divers working, Vestal's party operated until 02:00 on 7 September and reported the damage as a series of splits extending along some 150 feet (46 m) of the ship's bottom.

By the next morning, 8 September, Vestal's skilled repairmen, together with men of the battleship's crew, managed to mend the damage sufficiently to allow the ship to return to the United States for permanent repairs.

When Saratoga put into Tongatapu after being torpedoed by I-26 on 31 August, Vestal's divers combined forces with USS Navajo to inspect the damage and later trim and brace the hole.

Pumps managed to clear the water out of the flooded fire room and tons of cement were poured into the hole to patch the damaged area.

Her craftsmen repaired the wardroom (removing Mahan's anchor in the process), patched shrapnel holes, and put sprung hatches and damaged fire mains in order.

During her time at Nouméa, Vestal completed 158 jobs on 21 ships; she departed that port on 13 November; reached Espiritu Santo three days later; and began a year's schedule of repair service.

There were: San Francisco, ripped by heavy caliber hits during the night battle off Savo Island on 13 November 1942; New Orleans and Pensacola, the latter with a torpedo hole measuring 24 by 40 feet (12 m), a flooded after engine room, and two propeller shafts broken; the New Zealand light cruiser HMNZS Achilles - already famous for her part in the 1939 Battle of the River Plate and the subsequent sinking of the German pocket battleship Graf Spee - which, besides shrapnel and collision damage, had taken a direct hit on her after turret; and the torpedoed and fire-damaged cargo ship Alchiba.

"So it went", continued the commanding officer, "... one broken, twisted, torpedoed, burned ship after another was repaired well enough to make a navy yard or put back on the firing line."

Upon conclusion of those repairs, the addition of new equipment, alterations, a general overhaul, and a vari-colored paint job, Vestal departed Mare Island on 8 September, bound for the Carolines.

Her biggest repair job of that time was the light cruiser Reno, torpedoed off San Bernardino Strait by Japanese submarine I-41 on the night of 3 November.

Once again, Vestal's workers performed their tasks quickly and efficiently, having Reno on her way in a short time for permanent repairs in a stateside yard.

Underway for the Marianas on 25 February 1945, Vestal arrived at Saipan two days later, to commence what would be over two months of service there, principally repairing amphibious craft used for the Iwo Jima invasion.

During May, Vestal went to general quarters 59 times as Japanese planes made suicide attacks on the ships engaged in the bitter Okinawa campaign.

Experience proved that the best defense against the suiciders was a smoke or fog screen produced by all ships that blended into one gigantic mass of low-hanging clouds.

Besides the danger posed by suiciders, deck sentries kept a sharp lookout for any enemy who might attempt to swim out to the ships with mines or explosive charges.

Vestal remained at Kerama Retto through mid-June before she got underway on the 23d for Nakagusuku Wan, later renamed Buckner Bay, arriving there later that same day.

On 16 September, Vestal sortied for the third time on typhoon evasion, returning to the harbor the next day after having ridden out 68-knot (126 km/h) winds and heavy seas.

Upon receipt of orders from Commander, Service Division 104, Vestal weighed anchor and headed out to sea at 15:00, her stem sluicing seaward from Buckner Bay.

The merchantmen Fleetwood and Kenyan Victory took positions 800 yards (730 m) astern and in single file with Vestal leading the way, steaming westward and away from the threatening blackness massing to the east of Okinawa.

The ships met the fierce winds head-on to lessen the roll and steered to take the surging seas on the quarter, maneuvering skillfully to prevent damage or, worse, loss.

At 00:15 on the 7th, Vestal and all ships present in Buckner Bay received word to prepare to execute typhoon plan "X-ray" upon one hour's notice.

At that time, Vestal was steering a "crazy-patch course", eluding the storm that included seas up to 40 feet (12 m) high and winds registering between 50 and 65 knots (120 km/h).

At 14:05 on 10 October, while Vestal headed back to Buckner Bay, a signalman on the flying bridge called out: "Life raft on port bow."

Subsequently, Vestal performed her vital service functions supporting the occupation of China and Japan, before she sailed back to the United States.