After fitting out, the aircraft carrier trained in Hampton Roads, Virginia and in the southern drill grounds off the Virginia capes into January 1938, conducting carrier qualifications for her newly embarked air group.
Yorktown sailed for the Caribbean on 8 January 1938 and arrived at Culebra, Puerto Rico, on 13 January. Over the ensuing month, the carrier conducted her shakedown, touching at Charlotte Amalie, St Thomas, U.S. Virgin Islands; Gonaïves, Haiti; Guantanamo Bay, Cuba, and Cristóbal, Panama Canal Zone. Departing Colon Bay, Cristobal, on 1 March, Yorktown sailed for Hampton Roads, arrived on 6 March, and shifted to the Norfolk Navy Yard the next day for post-shakedown availability.
After undergoing repairs through the early autumn of 1938, Yorktown shifted from the navy yard to NOB Norfolk on 17 October and soon headed for the Southern Drill Grounds for training.
Yorktown operated off the eastern seaboard, ranging from Chesapeake Bay to Guantanamo Bay, into 1939. As flagship for Carrier Division 2, she participated in her first war game - Fleet Problem XX - along with her sister-ship in February 1939. The scenario for the exercise called for one fleet to control the sea lanes in the Caribbean against the incursion of a foreign European power while maintaining sufficient naval strength to protect vital American interests in the Pacific. The maneuvers were witnessed, in part, by President Franklin Delano Roosevelt, embarked in the heavy cruiser .
The critique of the operation revealed that carrier operations - a part of the scenarios for the annual exercises since the entry of into the war games in 1925 - had achieved a new peak of efficiency. Despite the inexperience of Yorktown and Enterprise - comparative newcomers to the Fleet - both carriers made significant contributions to the success of the problem. The planners had studied the employment of carriers and their embarked air groups in connection with convoy escort, antisubmarine defense, and various attack measures against surface ships and shore installations. In short, they worked to develop the tactics that would be used when war actually came.
Fleet Problem XXI - a two-part exercise - included some of the operations that would characterize future warfare in the Pacific. The first part of the exercise was devoted to training in making plans and estimates; in screening and scouting; in coordination of combatant units; and in employing fleet and standard dispositions. The second phase included training in convoy protection, the seizure of advanced bases, and, ultimately, the decisive engagement between the opposing fleets. The last pre-war exercise of its type, Fleet Problem XXI, contained two exercises (comparatively minor at the time) where air operations played a major role. Fleet Joint Air Exercise 114A prophetically pointed out the need to coordinate Army and Navy defense plans for the Hawaiian Islands, and Fleet Exercise 114 proved that aircraft could be used for high altitude tracking of surface forces - a significant role for planes that would be fully realized in the war to come.
With the retention of the Fleet in Hawaiian waters after the conclusion of Fleet Problem XXI, Yorktown operated in the Pacific off the west coast of the United States and in Hawaiian waters until the following spring, when the success of German U-boats preying upon British shipping in the Atlantic required a shift of American naval strength. Thus, to reinforce the U.S. Atlantic Fleet, the Navy transferred a substantial force from the Pacific including Yorktown, Battleship Division Three (the New Mexico class battleships), three light cruisers, and 12 accompanying destroyers.
Although Adolf Hitler had forbidden his submarines to attack American ships, the men who manned the American naval vessels were not aware of this policy and operated on a wartime footing in the Atlantic.
On 28 October, while Yorktown, battleship , and other American warships were screening a convoy, a destroyer picked up a submarine contact and dropped depth charges while the convoy itself made an emergency starboard turn, the first of the convoy's three emergency changes of course. Late that afternoon, engine repairs to one of the ships in the convoy, Empire Pintail, reduced the convoy's speed to .
During the night, the American ships intercepted strong German radio signals, indicating submarines probably in the vicinity reporting the group. Rear Admiral H. Kent Hewitt, commanding the escort force, sent a destroyer to sweep astern of the convoy to destroy the U-boat or at least to drive him under.
The next day, while cruiser scout planes patrolled overhead, Yorktown and fueled their escorting destroyers, finishing the task as dusk fell. On 30 October, Yorktown was preparing to fuel three destroyers when other escorts made sound contacts. The convoy subsequently made 10 emergency turns while and dropped depth charges, and assisted in developing the contact. Anderson later made two more depth charge attacks, noticing "considerable oil with slick spreading but no wreckage."
The short-of-war period was becoming more like the real thing as each day went on. Elsewhere on 30 October and more than a month before Japanese planes attacked Pearl Harbor, U-562 torpedoed the destroyer , sinking her with a heavy loss of life - the first loss of an American warship in World War II.
After another Neutrality Patrol stint in November, Yorktown put into Norfolk on 2 December and was there five days later when American fighting men in Hawaii were rudely awakened to find their country at war.
The early news from the Pacific was bleak: the Pacific Fleet had taken a beating. With the battle line crippled, the undamaged American carriers assumed great importance. There were, on 7 December, only three in the Pacific: , , and . , , and the recently commissioned remained in the Atlantic, Yorktown departed Norfolk on 16 December 1941 for the Pacific, her secondary gun galleries studded with new Oerlikon 20 mm guns. She reached San Diego 30 December 1941 and soon became flagship for Rear Admiral Frank Jack Fletcher's newly formed Task Force 17.
The carrier's first mission in her new theater was to escort a convoy carrying Marine reinforcements to American Samoa. Departing San Diego on 6 January 1942, Yorktown and her consorts covered the movement of marines to Tutuila and Pago Pago to augment the garrison already there.
Having safely covered that troop movement, Yorktown, in company with sister ship Enterprise, departed Samoan waters on 25 January. Six days later, TF8 (built around Enterprise), and TF17 (around Yorktown) parted company. The former headed for the Marshall Islands, the latter for the Gilberts, each to take part in some of the first American offensives of the war, the Marshalls-Gilberts raids.
At 05:17, Yorktown - screened by and and four destroyers - launched 11 Douglas TBD-1 Devastators and 17 Douglas SBD-3 Dauntlesses, under the command of Comdr. Curtis W. Smiley. Those planes hit what Japanese shore installations and shipping they could find at Jaluit, but severe thunderstorms hampered the mission, and seven planes were lost. Other Yorktown planes attacked Japanese installations and ships at Makin and Mili Atolls.
The attack on the Gilberts by TF17 had apparently been a complete surprise since the American force encountered no enemy surface ships. A single four-engined Kawanishi H6K "Mavis" patrol flying boat attempted to attack American destroyers sent astern in hope of recovering the crews of planes overdue from the Jaluit mission. Antiaircraft fire from the destroyers drove off the intruder before he could cause any damage.
Later, another "Mavis"-or possibly the same one-came out of low clouds distant from Yorktown. The carrier withheld her antiaircraft fire in order not to interfere with the combat air patrol (CAP) fighters. Presently, the "Mavis", pursued by two F4F Wildcats, disappeared behind a cloud. Within five minutes, the enemy patrol plane fell out of the clouds and crashed in the water.
Although TF17 was slated to make a second attack on Jaluit, it was canceled because of heavy rainstorms and the approach of darkness. Therefore, the Yorktown force retired from the area.
Admiral Chester Nimitz later called the Marshalls-Gilberts raids "well conceived, well planned, and brilliantly executed." The results obtained by TFs 8 and 17 were noteworthy, Nimitz continued in his subsequent report, because the task forces had been obliged to make their attacks somewhat blindly, due to lack of hard intelligence data on the Japanese-mandated islands.
Yorktown subsequently put in at Pearl Harbor for replenishment before she put to sea on 14 February, bound for the Coral Sea. On 6 March, she rendezvoused with TF11 - formed around Lexington and under the command of Rear Admiral Wilson Brown - and headed towards Rabaul and Gasmata to attack Japanese shipping there in an effort to check the Japanese advance and to cover the landing of Allied troops at Nouméa, New Caledonia. However, as the two carriers - screened by a powerful force of eight heavy cruisers (including the Australian HMAS Australia and 14 destroyers - steamed toward New Guinea, the Japanese continued their advance toward Australia with a landing on 7 March at the Huon Gulf, in the Salamaua-Lae area on the eastern end of New Guinea.
Word of the Japanese operation prompted Admiral Brown to change the objective of TF11's strike from Rabaul to the Salamaua-Lae sector. On the morning of 10 March 1942, American carriers launched aircraft from the Gulf of Papua. Lexington flew off her air group commencing at 07:49 and, 21 minutes later, Yorktown followed suit. While the choice of the gulf as the launch point for the strike meant the planes would have to fly some across the Owen Stanley mountains - a range not known for the best flying conditions - that approach provided security for the task force and ensured surprise.
In the attacks that followed, Lexington's SBDs from Scouting Squadron 2 (VS-2) commenced dive-bombing Japanese ships at Lae at 0922. The carrier's torpedo and bomber squadrons (VT-2 and VB-2) attacked shipping at Salamaua at 09:38. Her fighters (VF-2) split up into four-plane attack groups: one strafed Lae and the other, Salamaua. Yorktown's planes followed on the heels of those from "Lady Lex." VB-5 and VT-5 attacked Japanese ships in the Salamaua area at 0950, while VS-5 went after auxiliaries moored close in shore at Lae. The fighters of VF-42 flew CAP over Salamaua until they determined there was no air opposition, then strafed surface objectives and small boats in the harbor.
After carrying out their missions, the American planes returned to their carriers, and 103 planes of the 104 launched were back safely on board by noon. One SBD-2 had been downed by Japanese antiaircraft fire. The raid on Salamaua and Lae was the first attack by many pilots of both carriers; and, while the resultant torpedo and bombing accuracy was inferior to that achieved in later actions, the operation gave the fliers invaluable experience which enabled them to do so well in the Battle of the Coral Sea and the Battle of Midway.
Task Force 11 retired at on a southeasterly course until dark, when the ships steered eastward at and made rendezvous with Task Group 11.7 (TG11.7), four heavy cruisers and four destroyers under the Australian Rear Admiral John Crace, which provided cover for the carriers on their approach to New Guinea.
Yorktown resumed her patrols in the Coral Sea area, remaining at sea into April, out of reach of Japanese land-based aircraft and ready to carry out offensive operations whenever the opportunity presented itself. After the Lae-Salamaua raid, the situation in the South Pacific seemed temporarily stabilized, and Yorktown and her consorts in TF17 put in to the undeveloped harbor at Tongatapu, in the Tonga Islands, for needed upkeep, having been at sea continuously since departing from Pearl Harbor on 14 February.
However, the enemy was soon on the move. To Admiral Nimitz, there seemed to be "excellent indications that the Japanese intended to make a seaborne attack on Port Moresby the first week in May." Yorktown accordingly departed Tongatapu on 27 April 1942, bound once more for the Coral Sea. TF11 - now commanded by Rear Admiral Aubrey W. Fitch, who had relieved Brown in Lexington - departed Pearl Harbor to join Fletcher's TF 17 and arrived in the vicinity of Yorktown's group, southwest of the New Hebrides Islands, on 1 May.
On the morning of 3 May, TF11 and TF17 were some apart, engaged in fueling operations. Shortly before midnight, Fletcher received word from Australian-based aircraft that Japanese transports were disembarking troops and equipment at Tulagi in the Solomon Islands. Arriving soon after the Australians had evacuated the place, the Japanese landed to commence construction of a seaplane base there to support their southward thrust.
Yorktown accordingly set course northward at . By daybreak on 4 May, she was within striking distance of the newly established Japanese beachhead and launched her first strike at 0701-18 F4F-3's of VF-42, 12 TBD's of VT-5, and 28 SBD's from VS and BY-5. Yorktown's air group made three consecutive attacks on enemy ships and shore installations at Tulagi and Gavutu on the south coast of Florida Island in the Solomons. Expending 22 torpedoes and 76 1,000 pound bombs in the three attacks, Yorktown's planes sank the destroyer Kikuzuki, three minecraft and four barges. In addition, Air Group 5 destroyed five enemy seaplanes, all at the cost of two F4F's lost (the pilots were recovered) and one TBD (whose crew was lost).
Meanwhile, that same day, TF 44, a cruiser-destroyer force under Rear Admiral Crace (RN), joined Lexington's TF11, thus completing the composition of the Allied force on the eve of the crucial Battle of the Coral Sea.
Elsewhere, to the northward, eleven troop-laden transports - escorted by destroyers and covered by the light carrier Shōhō, four heavy cruisers, and a destroyer - steamed toward Port Moresby. In addition, another Japanese task force - formed around the two Pearl Harbor veterans, carriers Shōkaku and Zuikaku, and screened by two heavy cruisers and six destroyers - provided additional air cover.
On the morning of 6 May, Fletcher gathered all Allied forces under his tactical command as TF17. At daybreak on the 7th, he dispatched Crace, with the cruisers and destroyers under his command, toward the Louisiade archipelago to intercept any enemy attempt to move toward Port Moresby.
While Fletcher moved north with his two flattops and their screens in search of the enemy, Japanese search planes located the oiler and her escort, and misidentified the former as a carrier. Two waves of Japanese planes — first high level bombers and then dive bombers — attacked the two ships. Sims, her antiaircraft battery crippled by gun failures, took three direct hits and sank quickly with a heavy loss of life. Neosho was more fortunate in that, even after seven direct hits and eight near-misses, she remained afloat until, on the 11th, her survivors were picked up by and her hulk sunk by the rescuing destroyer.
Neosho and Sims had performed a valuable service, drawing off the planes that might otherwise have hit Fletcher's carriers. Meanwhile, Yorktown and Lexington's planes found Shōhō and sunk her. One of Lexington's pilots reported this victory with the radio message, "Scratch one flattop".
That afternoon, Shōkaku and Zuikaku - still not located by Fletcher's forces - launched 27 bombers and torpedo planes to search for the American ships. Their flight proved uneventful until they ran into fighters from Yorktown and Lexington, who proceeded to down nine enemy planes in the ensuing dogfight.
Near twilight, three Japanese planes incredibly mistook Yorktown for their own carrier and attempted to land. The ship's gunfire, though, drove them off; and the enemy planes crossed Yorktown's bow and turned away out of range. Twenty minutes later, when three more enemy pilots made the mistake of trying to get into Yorktown's landing circle, the carrier's gunners splashed one of the trio.
However, the battle was far from over. The next morning, 8 May, a Lexington search plane spotted Admiral Takagi's carrier striking force - including Zuikaku and Shōkaku. Yorktown planes scored two bomb hits on Shōkaku, damaging her flight deck and preventing her from launching aircraft; in addition, the bombs set off explosions in gasoline storage tanks and destroyed an engine repair workshop. Lexington's Dauntlesses added another hit. Between the two American air groups, the hits killed 108 Japanese sailors and wounded 40 more.
While the American planes were occupying the Japanese flattops, however, Yorktown and Lexington - alerted by an intercepted message which indicated that the Japanese knew of their whereabouts - were preparing to fight off a retaliatory strike, which came shortly after 11:00.
American CAP Wildcats downed 17 planes, though some managed to slip through the defenses. "Kates" launched torpedoes from both sides of Lexington's bows. Two "fish" tore into "Lady Lex" on the port side; "Val" dive bombers added to the destruction with three bomb hits. Lexington developed a list, with three partially-flooded engineering spaces. Several fires raged below decks, and the carrier's elevators were put out of commission.
Meanwhile Yorktown was having problems of her own. Maneuvered by Captain Elliott Buckmaster, her commanding officer, the carrier dodged eight torpedoes. Attacked then by "Vals", the ship managed to evade all but one bomb. That one, however, penetrated the flight deck and exploded below decks, killing or seriously injuring 66 men.
Lexington's damage control parties brought the fires under control, and the ship was still able to continue flight operations despite the damage. The air battle itself ended shortly before noon on the 8th; within an hour, the carrier was on an even keel, although slightly down by the bow. However, an explosion caused by the ignition of gasoline vapors later caused a fire and tore apart the inside. Lexington was abandoned at 1707, and later sunk by .
The Japanese had won a tactical victory, inflicting comparatively heavier losses on the Allied force, but the Allies, in stemming the tide of Japan's conquests in the South and Southwest Pacific, had achieved a strategic victory. Yorktown had not achieved her part in the victory without cost, and had suffered enough damage to cause experts to estimate that at least three months in a yard would be required to put her back in fighting trim. However, there was little time for repairs, because Allied intelligence - most notably the cryptographic unit at Pearl Harbor - had gained enough information from decoded Japanese naval messages to estimate that the Japanese were on the threshold of a major operation aimed at the northwestern tip of the Hawaiian chain - two islets in a low coral atoll known as Midway.
Armed with this intelligence Admiral Nimitz began methodically planning Midway's defense, rushing all possible reinforcement in the way of men, planes and guns to Midway. In addition, he began gathering his naval forces - comparatively meager as they were - to meet the enemy at sea. As part of those preparations, he recalled TF16, Enterprise and Hornet (CV-8), to Pearl Harbor for a quick replenishment.
Yorktown, too, received orders to return to Hawaii; and she arrived at Pearl Harbor on 27 May. Performing a seeming miracle, yard workers there - laboring around the clock - made enough repairs to enable the ship to put to sea. Her air group - for the most part experienced but weary - was augmented by planes and crews from Saratoga (CV-3) which was then headed for Hawaiian waters after her modernization on the west coast. Ready for battle, Yorktown sailed as the core of TF17 on 30 May.
Northeast of Midway, Yorktown, flying Rear Admiral Fletcher's flag, rendezvoused with TF16 under Rear Admiral Raymond A. Spruance and maintained a position to the northward of him.
Patrols, both from Midway itself and from the carriers, proceeded apace during those days in early June. On the morning of the 4th as dawn began to streak the eastern sky, Yorktown launched a 10-plane group of Dauntlesses from VB-5 which searched a northern semicircle for a distance of out but found nothing.
Meanwhile, PBYs flying from Midway had sighted the approaching Japanese and broadcast the alarm for the American forces defending the key atoll. Admiral Fletcher, in tactical command, ordered Admiral Spruance's TF16 to locate the enemy carrier force and strike them as soon as they were found.
Yorktown's search group returned at 0830, landing soon after the last of the six-plane CAP had left the deck. When the last of the Dauntlesses were recovered, the deck was hastily respotted for the launch of the ship's attack group - 17 Dauntlesses from VB-3; 12 Devastators from VT-3, and six Wildcats from "Fighting Three." Enterprise and Hornet, meanwhile, launched their attack groups.
The torpedo planes from the three American carriers located the Japanese striking force, but met disaster. Of the 41 planes from VT-8, VT-6, and VT-3, only six returned to Enterprise and Yorktown, collectively. None made it back to Hornet.
The destruction of the torpedo planes, however, had served a purpose. The Japanese CAP had broken off their high-altitude cover for their carriers and had concentrated on the Devastators, flying "on the deck." The skies above were thus left open for Dauntlesses arriving from Yorktown and Enterprise.
Virtually unopposed, Yorktown's dive-bombers pummeled , making three lethal hits with 1,000 pound bombs, turning her into an inferno. Enterprise's planes, meanwhile, hit and - turning them, too into wrecks in short order. The bombs from the Dauntlesses caught all of the Japanese carriers in the midst of refueling and rearming operations, and the combination of bombs and gasoline proved explosive and disastrous to the Japanese.
Three Japanese carriers had been lost. A fourth however, still roamed at large - . Separated from her sisters, she launched a striking force of 18 "Vals" and soon located Yorktown.
As soon as the attackers had been picked up on Yorktown's radar at about 1329, she discontinued fueling her CAP fighters on deck and swiftly cleared for action. Her returning dive bombers were moved from the landing circle to open the area for antiaircraft fire. The Dauntlesses were ordered aloft to form a CAP. An auxiliary gasoline tank - of 800 gallons capacity - was pushed over the carrier's fantail, eliminating one fire hazard. The crew drained fuel lines and closed and secured all compartments.
All of Yorktown's fighters were vectored out to intercept the oncoming Japanese aircraft, and did so some 15 to out. The Wildcats attacked vigorously, breaking up what appeared to be an organized attack by some 18 "Vals" and 18 "Zeroes." "Planes were flying in every direction", wrote Captain Buckmaster after the action, "and many were falling in flames." The leader of the "Vals", Lieutenant Joichi Tomonaga, was probably shot down by the VF-3's commanding officer, Lieutenant Commander John S. Thach.
Despite an intensive barrage and evasive maneuvering, three "Vals" scored hits. Two of them were shot down soon after releasing their bomb loads; the third went out of control just as his bomb left the rack. It tumbled in flight and hit just abaft number two elevator on the starboard side, exploding on contact and blasting a hole about square in the flight deck. Splinters from the exploding bomb decimated the crews of the two gun mounts aft of the island and on the flight deck below. Fragments piercing the flight deck hit three planes on the hangar deck, starting fires. One of the aircraft, a Yorktown Dauntless, was fully fueled and carrying a 1,000 pound bomb. Prompt action by Lt. A. C. Emerson, the hangar deck officer, prevented a serious conflagration by activating the sprinkler system and quickly extinguishing the fire.
The second bomb to hit the ship came from the port side, pierced the flight deck, and exploded in the lower part of the funnel. It ruptured the uptakes for three boilers, disabled two boilers themselves, and extinguished the fires in five boilers. Smoke and gases began filling the firerooms of six boilers. The men at number one boiler, however, remained at their post despite their danger and discomfort and kept its fire going, maintaining enough steam pressure to allow the auxiliary steam systems to function.
A third bomb hit the carrier from the starboard side, pierced the side of number one elevator and exploded on the fourth deck, starting a persistent fire in the rag storage space, adjacent to the forward gasoline stowage and the magazines. The prior precaution of smothering the gasoline system with carbon dioxide undoubtedly prevented the gasoline from igniting.
While the ship recovered from the damage inflicted by the dive-bombing attack, her speed dropped to six knots; and then at 14:40, about 20 minutes after the bomb hit that had shut down most of the boilers, Yorktown slowed to a stop, dead in the water.
At about 15:40, Yorktown prepared to get steaming again; and, at 1550, the engine room force reported that they were ready to make or better. The ship was not yet out of the fight.
Simultaneously, with the fires controlled sufficiently to warrant the resumption of fueling, Yorktown began refueling the fighters then on deck; just then the ship's radar picked up an incoming air group at a distance of . While the ship prepared for battle - again smothering gasoline systems and stopping the fueling of the planes on her flight deck - she vectored four of the six fighters of the CAP in the air to intercept the raiders. Of the 10 fighters on board, eight had as little as 23 gallons of fuel in their tanks. They were launched as the remaining pair of fighters of the CAP headed out to intercept the Japanese planes.
At 16:00, maneuvering Yorktown churned forward, making . The fighters she had launched and vectored out to intercept had meanwhile made contact with the enemy. Yorktown received reports that the planes were "Kates." The Wildcats shot down at least three, but the rest began their approach while the carrier and her escorts mounted a heavy antiaircraft barrage.
Yorktown maneuvered radically, avoiding at least two torpedoes before another two tore struck the port side within minutes of each other, the first at 16:20. The carrier had been mortally wounded; she lost power and went dead in the water with a jammed rudder and an increasing list to port.
As the list progressed Commander C. E. Aldrich, the damage control officer, reported from central station that, without power, controlling the flooding looked impossible. The engineering officer, Lt. Cdr. J. F. Delaney, soon reported that all fires were out, but all power was lost and it was impossible to correct the list. Buckmaster ordered Aldrich, Delaney, and their men to secure and lay up on deck to put on life jackets.
The list, meanwhile, continued to increase. When it reached 26 degrees, Buckmaster and Aldrich agreed that capsizing was imminent. "In order to save as many of the ship's company as possible", the captain wrote later, he "ordered the ship to be abandoned."
Over the next few minutes the crew lowered the wounded into life rafts and struck out for the nearby destroyers and cruisers to be picked up by their boats, abandoning ship in good order. After the evacuation of all wounded, the executive officer, Commander I. D. Wiltsie, left the ship down a line on the starboard side. Buckmaster, meanwhile, toured the ship one last time, to see if any men remained. After finding no "live personnel", Buckmaster lowered himself into the water by means of a line over the stern, by which time water was lapping the port side of the hangar deck.
After being picked up by the destroyer , Buckmaster transferred to and reported to Rear Admiral Fletcher, who had shifted his flag to the heavy cruiser after the first dive-bombing attack. The two men agreed that a salvage party should attempt to save the ship, since she had stubbornly remained afloat despite the heavy list and imminent danger of capsizing.
While efforts to save Yorktown had been proceeding apace, her planes were still in action, joining those from in striking the last Japanese carrier - Hiryū - late that afternoon. Taking four direct hits, the Japanese carrier was soon helpless. She was abandoned by her crew and left to drift out of control.
Yorktown, as it turned out, floated throughout the night. Two men were still alive on board her; one attracted attention by firing a machine gun, heard by the sole attending destroyer, Hughes. The escort picked up the men, one of whom later died.
Meanwhile, Buckmaster had selected 29 officers and 141 men to return to the ship in an attempt to save her. Five destroyers formed an antisubmarine screen while the salvage party boarded the listing carrier, the fire in the rag storage still smouldering on the morning of the 6th. , summoned from Pearl and Hermes Reef, soon commenced towing the ship. Progress, though, was painfully slow.
Yorktown's repair party went on board with a carefully predetermined plan of action to be carried out by men from each department - damage control, gunnery air engineering, navigation, communication, supply and medical. To assist in the work, Lt. Cdr. Arnold E. True brought his ship, , alongside to starboard, aft, furnishing pumps and electric power.
By mid-afternoon, it looked as if the gamble to save the ship was paying off. The process of reducing topside weight was proceeding well - one gun had been dropped over the side, and a second was ready to be cast loose; planes had been pushed over the side; the submersible pumps (powered by electricity provided by Hammann) had pumped a lot of water out of the engineering spaces. The efforts of the salvage crew had reduced the list about two degrees.
Unknown to Yorktown and the six nearby destroyers, had achieved a favorable firing position. Remarkably - but perhaps understandably due to the debris and wreckage in the water in the vicinity - none of the destroyers picked up the approaching I-boat. At 15:36 lookouts spotted a salvo of four torpedoes approaching the ship from the starboard beam.
Hammann went to general quarters, a 20 millimeter gun going into action in an attempt to explode the torpedoes in the water. One torpedo hit Hammann - her screws churning the water beneath her fantail as she tried to get underway - directly amidships and broke her back. The destroyer jackknifed and went down rapidly.
Two torpedoes struck Yorktown just below the turn of the bilge at the after end of the island structure. The fourth torpedo passed just astern of the carrier.
About a minute after Hammann sank there was an underwater explosion, possibly caused by the destroyer's depth charges going off. The blast killed many of Hammann's and a few of Yorktown's men who had been thrown into the water. The concussion battered the already-damaged carrier's hull and caused tremendous shocks that carried away Yorktown's auxiliary generator, sent numerous fixtures from the hangar deck overhead crashing to the deck below, sheared rivets in the starboard leg of the foremast, and threw men in every direction, causing broken bones and several minor injuries.
All destroyers immediately commenced searches for the enemy submarine (which escaped) and commenced rescuing men from Hammann and Yorktown. Captain Buckmaster decided to postpone further attempts at salvage until the following day.
Vireo cut the tow and doubled back to Yorktown to pick up survivors, taking on board many men of the salvage crew while picking up men from the water. The little ship endured a terrific pounding from the larger ship but nevertheless stayed alongside to carry out her rescue mission. Later, while on board the tug, Buckmaster conducted a burial service, and two officers and an enlisted man from Hammann were buried at sea.
The second attempt at salvage was never made. Throughout the night of the 6th and into the morning of the 7th, Yorktown remained stubbornly afloat. By 05:30 on 7 June, however, the men in the ships nearby noted that the carrier's list was rapidly increasing to port. At 07:01, the ship turned over onto her port side and sank in 3,000 fathoms (5,500 m) of water, her battle flags flying.
On 19 May 1998, the wreck of Yorktown was found and photographed by renowned oceanographer Dr. Robert D. Ballard, discoverer of the wreck of the . The wreck, beneath the surface, was surprisingly intact after having been on the sea bottom since 1942—much paint and equipment were still visible.