How the US Navy Helped Find Titanic and Other Sunken Ships

2. USS Scorpion, another nuclear submarine, was lost in May, 1968

USS Scorpion was a Skipjack class nuclear submarine due to return to its homeport of Norfolk in May, 1968. When the Navy announced that the submarine was overdue, and that its last transmission had been received on May 21, speculation over its disappearance ran rampant. On June 5 the Navy announced Scorpion was presumed lost, and on June 30 the vessel was stricken from the Navy’s registry of ships. A search began, which used the sounds of explosions recorded by undersea sonar. By October it was agreed that Scorpion had been sunk on May 22, 1968, and its final resting place was known to the Navy.

By 1969 the official Navy findings were that Scorpion was destroyed when it passed its designed crush depth, due to uncontrolled flooding. The cause of the flooding was undetermined. This led to the development of numerous theories within and outside the Navy, including speculation that the submarine had been sunk by Soviet ships it had been tasked with observing, an underwater torpedo battle, a shipboard torpedo accident, and several others. The Navy took extensive photographs of the wreck site, which in 1985 remained classified. The Navy did point out that the sounds recorded by the undersea sonar (SOSUS) were not those of explosions, but of implosions as the hull was crushed.

3. USS Thresher and USS Scorpion remained of interest to the American and Soviet Navies during the Cold War

USS Thresher and USS Scorpion were both equipped to carry nuclear weapons during their periods of service. Though the US Navy never officially acknowledged whether or not nuclear weapons were aboard any vessel at any time the likelihood is the Scorpion at least was so armed as it was returning from the Mediterranean when it sank. Thresher may well not have been, since it was in a maintenance cycle. However, both ships contained nuclear reactors, as well as classified material and equipment. It was in the interests of the Soviet Navy to obtain them if possible, and it was in the interest of the US Navy to ensure that didn’t happen.

Scorpion was of particular interest due to the unknown nature of the incident which triggered its loss. Though both submarines were very deep beneath the surface (Scorpion is almost 10,000 feet below), the United States and the Soviet Union worked throughout the Cold War to develop deep submergence capabilities. Surface ship activity in the area of Scorpion’s loss by either side brought the watchful eye of the other. Thresher, about 220 miles off Cape Cod, was more easily guarded by US Navy and Coast Guard patrols and aircraft.

4. Dr. Robert Ballard was an officer in the United States Naval Reserve

Robert Ballard was a reserve US Naval officer working at the Woods Hole Oceanographic Institute when he designed a remotely controlled submersible named Argo. The vessel could scan the ocean floor using sonar and carry a camera system. Ballard had long had an interest in finding the last resting place of RMS Titanic, and he approached the Navy to demonstrate the capabilities of Argo and request the Navy help support a search for the long-lost passenger liner in 1982. The Navy turned him down, having little interest in searching for a lost British liner, which at the time was all but forgotten by most of the general public.

What had happened to USS Scorpion, and a better view of the wreckage of USS Thresher, was of interest to the Navy, however. The Deputy Chief of Naval Operations for Submarine Warfare, Robert Thunman, told Ballard that the Navy would be interested in using Argo, in a secret operation, to obtain data from the sites of both wrecked submarines. When Ballard agreed he was assigned to active duty, and tasked with surveying both sites. Secretary of the Navy John Lehman was apprised of the plan, which was so highly classified that several of the crew of the vessel which was to be used were unaware of its existence.

5. The Navy claimed Scorpion had been lost due to an accident

In 1982 the official US Navy explanation for the loss of USS Scorpion was that it was an accidental explosion of a torpedo, which occurred as the submarine took steps to disarm it. According to one senior official heavily involved in both the search for the lost submarine and the subsequent analysis of what caused its loss, it was the “one scenario that, in my opinion, fits all of the evidence”. But dissent with the finding remained within the ranks of the submarine force and among outside experts, as well as conspiracy buffs. The position was speculative, rather than confirmation.

Other elements within the Navy studied the findings, the data, and produced conflicting opinions of what they indicated. Rumors rippled that implied or outright stated that the Soviets had sunk the submarine. They were fueled in part by Scorpion’s loss being one of four unsolved submarine mysteries occurring in 1968, Israel’s Dakar, the French Navy’s Minerve, and the Soviet K-129 all sank that year in unexplained circumstances. The rumors, the dissenting opinions, and the Cold War were all reasons for the US Navy to want any additional information they could get on USS Scorpion.

6. The Navy agreed to let Ballard search for Titanic if there was time left after he completed his missions at the submarine wreck sites

Ballard lobbied the Navy to allow him to search for Titanic, the suspected site being in between that of Scorpion, southwest of the Azores, and Thresher, east of Cape Cod. The Navy balked, stressing that the mission’s primary reason for being was surveying the sites of the lost submarines. When it was pointed out that a search for RMS Titanic would provide a solid cover for the true intent of the mission, the Navy reconsidered. It was finally agreed that Ballard could use any remaining time in the scheduled mission to search for the Titanic only after all the mission requirements of the Navy had been met.

For the first phase of the mission, conducted in the summer of 1984, Ballard was to map the wrecks of USS Scorpion and USS Thresher towing Argo over the wreck using the research vessel RV Knorr. A close-up camera vehicle was tethered to Argo and named Jason. His mission was to establish that the reactors were intact, that nuclear weapons were still present, and, if possible, obtain additional information regarding what kind of catastrophic event occurred which triggered the chain of events which caused the submarine to be lost. The following year he was to return to Scorpion, after which he would be free to search for Titanic if there was any time remaining.

7. Ballard learned a mapping technique over Scorpion which helped find the Titanic

During the repeated passes over the sunken Scorpion, Ballard observed that a sinking vessel left a debris trail, which could be followed to find the main portion of wreckage, if there was one to be found. This trail occurred for the simple reason that heavier pieces of wreckage sank to the bottom faster than lighter debris. In previous searches for lost vessels, the main reliance had been on using bottom and side-scanning sonars to locate large objects and then investigating. Ballard discovered that the trail of smaller objects could be followed.

With Scorpion investigated and photographed, and the debris field mapped in 1985, RV Knorr departed the area south of the Azores and rendezvoused with the French research vessel Le Suroit, which had been scanning the area using side scan sonar. With twelve days remaining before the mission was over, Ballard decided to use the technique of following the debris trail, or trails, to find what remained of the massive ocean liner which had failed to complete a single voyage before sailing into eternity, taking with it over 1,500 souls.

8. Ballard believed there would be extensive debris trails around the Titanic

When Titanic made its final plunge to the bottom on the frigid morning of April 15, 1912, it was witnessed by hundreds of men, women, and children. Most of those who survived to relate their experiences to investigators, reporters, the crews of the rescue ships, and anyone else who would listen told tales which often varied in details. Many reported the ship plunged straight down, bow first. Others claimed that the ship slowly but steadily slipped beneath the surface. Others still claimed that the ship’s stern rose until, unable to bear its weight, the ship broke in half, with the stern resettling into the water before being pulled down by the sinking forward section.

Officially the White Star Line and Harlan and Woolf, the ship’s builder, denied the possibility of the ship breaking up, fearful of the public reaction toward the safety of their ships in general. There was no official finding that the ship broke in two. Ballard gambled the reports of the breaking apart were true, and reasoned that there should be, as a result, a substantial debris field, which once found would lead to the main sections of the wreck, as had occurred with Scorpion, which imploded underwater at crush depth, creating a debris field which led to the remains of the submarine.

9. The French did preliminary research over the suspected Titanic site in 1985

While Ballard was surveying the wreckage of Scorpion in the summer of 1985, his second mission to the submarine’s resting place, the French research team aboard Le Suroit worked in the area where Titanic was believed to have gone down, using side scan sonar. Ballard had tasked the French with finding and charting large targets, which he would investigate using Argo/Jason after his work was complete at the Scorpion site. The French steamed back and forth over the assigned area for five weeks, finding nothing of interest (when Ballard did finally locate the wreck he realized the closest the French had come was a few hundred yards).

Knorr sailed in a back-and-forth pattern over the area for a week, towing Argo, the cameras on which were monitored 24 hours per day. On the eighth day, and with just four remaining before the mission would be over, large items of debris were found on the ocean floor. On September 2, 1985, Titanic’s bow appeared on the screens, sent back by Argo. After 73 years, the lost Titanic had been found, an event which made headlines across the globe. There was no mention of the expedition’s visits to the sunken submarines, but those had delivered new information as well.

10. The expeditions to the sunken submarines provided information regarding their loss

The higher-resolution images obtained at the wreck of USS Thresher helped the Navy confirm that the investigators had been correct in establishing the cause of that vessel’s loss. A seawater piping joint, silver brazed rather than welded, failed and sprayed seawater on an electrical panel, causing a reactor shutdown and subsequent loss of power. When the crew tried to blow the seawater out of the main ballast tanks, moisture in the released high-pressure air caused valves to freeze, blocking airflow, and the submarine slipped, stern first, below crush depth. Photographs provided by Ballard confirmed the scenario.

Photographs and other information at the Scorpion site were not so informative in revealing the cause of the initial catastrophic event which led to the loss of the ship. But they did reveal that the visible portions of the hull were intact, with no evidence of an explosion either outside or internal to the submarine. The hull had telescoped at implosion, with the narrower stern section thrust deeply into the forward section. The official Navy conclusion remained that the ship was lost due to an unknown catastrophic event, but an attack on it by the Soviets (or anyone else) was not supported by the evidence.

11. US Navy personnel were covertly part of Ballard’s expedition

To map and study the sites of the two lost submarines, and Titanic, active duty US Navy personnel were assigned to the crew and to Ballard’s research team. The fact that these new and presumably unknown members of the team were active duty Navy was kept from the remaining members of Ballard’s team, though he was aware of it himself. Officially the time spent over the wrecks of the submarines was for training these new team members, in preparation for the time spent looking for the Titanic. The secrecy continued after the work was complete, and Ballard’s time spent on the operation was in his official capacity as an officer in the United States Navy.

The success of the operation at both the submarine sites and the Titanic site led the US Navy to use Argo/Jason and subsequently developed advanced technology for other missions, many of which remain classified. How much money the Navy spent in assisting to develop the technology and techniques used to find the Titanic is unknown outside of the Navy and its contractors. The Navy had been impressed that Argo/Jason worked so well at the 9,800-foot depth at which Scorpion lies. The Titanic’s wreckage is at a depth exceeding 12,000 feet.

12. The world was stunned by the discovery of Titanic’s wreck and subsequent examinations

Titanic had been the subject of several films before its wreckage was found, as well as historical reports and fictional works. Even the Nazi propaganda machine had made a film about the ship, which depicted upper-class British passengers acting in a cowardly and panicked manner as the ship went down, with lower-class passengers in steerage kept from the lifeboats at gunpoint. Many conflicting stories of the events of the night it struck the iceberg, the heavy loss of life, and the failings of the ship itself had developed before it was found. Once it was, international attention reached a point near that of the aftermath of its loss in 1912.

For decades it had been believed and was demonstrated in films, that the iceberg the ship had struck had torn a gash along the ship’s starboard side, flooding the ship’s four forwardmost compartments. Subsequent visits to the wreck established that the theory was incorrect. Instead, the impact had caused rivets holding the plates of the hull to the ribs and each other had been sprung and the resulting gap is what allowed the fatal flow of water into the hull. As the forward compartments flooded and the bow sank deeper into the water, each succeeding compartment overflowed into the one behind, like an ice cube tray sinking in a sink full of water.

13. Ballard’s expedition entered Titanic on a subsequent visit

In 1986 Ballard returned to Titanic using the research vessel Atlantis II, taking Argo with him. He was also accompanied by a deep submergence vehicle (DSV) named Alvin, which could carry people to the edge of the wreck, allowing a tethered remote vehicle named Jason Jr. to explore the interior. Jason Jr’s photographs of the interior of the wreck further piqued public interest as it sent back pictures of ghostly chandeliers, plates and crockery, and the Grand Staircase which it descended, sending back images as if it was walking down the stairs.

The public interest in the wreck, and the renewed interest in the story of Titanic, were both events that Ballard welcomed, but a rising chorus from investors and adventurers over salvaging artifacts from the site – even calls for salvaging the ship itself – caused a sense of alarm. To Ballard, the ship was a grave, and he considered keeping its location secret, but the graverobbers were not to be denied. By 1987 an expedition funded by American investors had recovered over 1,800 objects from the ship and debris field. By the end of the century, the number of items taken from the wreck site was in the tens of thousands.

14. The remarkable DSV Alvin once sunk itself and later recovered

When the exploration team entered the sunken Titanic in 1986, they did so in a submersible which had itself once been the victim of sinking. On October 16, 1968, Alvin was being lowered into the water by the US Navy tender USS Lulu, with three crew members aboard the DSV preparing for a dive. Steel cables lowering the submersible snapped, and the vessel sank in 5,000 feet of water, though the three men aboard were able to escape before it went down. The accident occurred about 100 miles to the South of Nantucket, and Alvin remained on the bottom throughout the winter.

In June of the following year, Alvin was located by USS Mizar. At the time nothing of the size of Alvin had been recovered from such a depth. In August the DSV Aluminaut was used in an attempt to recover Alvin, but rough seas in the aftermath of Hurricane Camille forced the recovery team to abandon the attempt. In late August a second attempt was made, and Alvin was raised to a depth of about forty feet, where it remained, tethered to USS Mizar, as it was towed to Woods Hole for repairs and to have installed a new pressure hull, manufactured of titanium, which allowed it reach yet greater depths.

15. The sinking of the German battleship Bismarck and Britain’s HMS Hood

In May, 1941, the German battleship Bismarck sailed on its only wartime mission, bound for the Atlantic shipping lanes to raid Allied convoys. In the Denmark Strait, the battleship and its consort, the heavy cruiser Prinz Eugen, encountered the new British battleship Prince of Wales and the battlecruiser Hood, which was at the time the largest and most powerful warship of the Royal Navy. In foul weather and limited visibility, Bismarck sank Hood in a short gun duel, the latter ship going down with the loss of all but three of her crew. Prince of Wales was badly damaged and forced to break off the fight. The Royal Navy mustered all of its available forces to track down and sink the German battleship.

On May 27, damaged by aircraft launched torpedoes and unable to steer, Bismarck was trapped by two British battleships, with supporting cruisers and destroyers in the vicinity. The German ship was battered into a flaming wreck before the Germans began to abandon the ship. Torpedoes from the cruiser Dorsetshire were launched into the ship as a coup de grace. The ship sank in an inaccurately reported position, with the British announcing they had sunk the vessel. Survivors from Bismarck claimed they had scuttled the ship when it could no longer fight back. The truth could not be verified, because for decades the sunken ship could not be found.

16. Ballard used the techniques developed for Scorpion to locate and explore Bismarck

In 1988 Ballard and his team began a search for the wreck of Bismarck, using the techniques developed in the exploration of the sunken Scorpion. The last violent moments of the German battleship were well documented by survivors from the German battleship and British naval records and observations, but the location of the wreck remained elusive. The search was inconclusive. Ballard returned to the site the following year near the end of May, and the search team found evidence of a massive avalanche down the side of a seamount, the source of which proved to be the huge battleship sliding down the side of the inactive volcanic mountain as it settled to the bottom.

The hull of the ship was upright, sitting two-thirds down the slope with its bow nearly buried in the debris of the avalanche. Ballard found the hull to be in remarkably good condition, intact other than a short section of the stern, which had broken off. The four turrets of the main battery had fallen out as the ship rolled over during sinking, and are on the bottom upside down near the hull. Ballard’s team announced the finding of the ship and released photographs of the wreckage, but refused to announce its precise location, in order to prevent the scavenging of the ship as was already happening to Titanic.

17. Ballard’s exploration provided physical evidence to support the scuttling of Bismarck

Since the German battleship was sunk by the Royal Navy in 1941, survivors claimed that the departing German crew had used scuttling charges to sink their ship. The Royal Navy discounted the claim, officially stating that torpedoes from HMS Dorsetshire had dealt the fatal blow. Ballard’s exploration of the wreck found the battleship’s armored citadel to be intact, with no evidence of penetration from torpedoes or shells, though the unarmored sections bore evidence of the severe damage inflicted by the British ships. There was also no evidence of compartments imploding from sea pressure as the ship sank.

Ballard’s findings from the physical condition of the wreck were consistent with the German claim of scuttling, an action in which explosive charges blow out the bottom of the hull, and watertight doors are opened to allow the entire hull to flood. Despite the ship being reduced to a flaming wreck by the British bombardment, its armor had successfully withstood the barrage. Had the Germans not scuttled the ship, it likely would have drifted as a burning wreck for a time impossible to estimate. Eventually, the location of the wreck became known, and the Federal Republic of Germany declared it to be their property and a war grave.

18. The sinking of USS Yorktown in June, 1942

In the spring of 1942 intelligence data developed by codebreakers allowed the US Navy to ambush the Imperial Japanese Navy when the latter attempted to invade Midway Atoll in the central Pacific. The Americans, in one of the most critical naval battles of history, destroyed four Japanese aircraft carriers, while suffering the loss of one, USS Yorktown. Yorktown had been heavily damaged during the Battle of Coral Sea the preceding month, and fought at Midway in a patched-together condition. Aircraft from Yorktown dealt fatal blows to the Japanese carrier Soryu. Yorktown was bombed severely, and for a time was dead in the water before damage control teams made the ship operational again.

Bombed yet again, with resulting loss of power, the ship was abandoned yet refused to sink. As it became apparent that the United States had won a major victory, a volunteer crew went back to Yorktown to try to control the fires and flooding, and prepare it to be towed into port for repairs. On June 6, Yorktown was under tow when a Japanese submarine attacked the escorting destroyer, Hammann, sinking it in minutes, and two torpedoes hit Yorktown. The ship rapidly listed to port, the towline was cast off, and the carrier was again abandoned. Early on the morning of June 7 the ship finally rolled onto its side and sank, into waters well over 15,000 feet deep.

19. The Yorktown search was the most difficult of all for Ballard’s research team

The waters which swallowed USS Yorktown are 16,650 feet deep, a mile deeper than those in which the wreck of Titanic was found in 1985. To find the wreck, an expedition was formed by the National Geographic Society, led by Dr. Ballard and supported by the US Navy, who assigned personnel to the team. The Navy’s participation provided valuable real-world training for operators of its underwater search vehicles and submarine rescue teams. Ballard used techniques developed during the Scorpion expedition and honed in other searches during the difficult search for the sunken aircraft carrier.

During the search for Titanic and even more so for the Bismarck wreckage, the technicians and researchers discovered that as a ship strikes the bottom it does not do so gently. Instead, it slams into the bottom, its velocity dependent on the depth it descended, and the violence displaces large amounts of mud and bottom debris. The mud is often displaced in a circular pattern around the wreck, with clots the size of huge boulders. Once a clot is sighted, additional clots are sought until the arc of the circle can be computed, allowing the search to then focus on the center, where the wreck is found.

20. Yorktown was found to be almost entirely intact, and in good condition

When the wreck of the World War II aircraft carrier USS Yorktown was discovered, it was found to be almost entirely clear of marine life and rust. The ship sits upright on the sea bottom, three miles beneath the surface. The entire flight deck was traversed, its surface unobscured. Stainless steel fittings and panels retained their shine as if waiting for inspection after 56 years. The US Navy ship supporting the operation, USNS Laney Chouest, was designed and fitted out for the support of US Navy deep submergence operations. Aboard was a veteran of the Battle of Midway, who had been one of the men who returned to the abandoned Yorktown in an attempt to save the ship in 1942.

He was able to positively identify the ship as the lost aircraft carrier, including identifying the catwalk from which he had abandoned the ship a second time after it was torpedoed by a Japanese submarine. The successful search for the lost Yorktown, like the other searches for lost ships that preceded it, made headlines. But it was a boon for the US Navy in other ways besides publicity. The Navy’s role in the search was known, but downplayed, as it was able to exercise its personnel and equipment in a situation near the technological limits due to the depth at which rests the sunken ship in the vast reaches of the Pacific.

21. The destruction of PT 109 in 1943

In the spring of 2002, Robert Ballard led an expedition to locate the wreck of PT 109, the motor torpedo boat commanded by Lieutenant Junior Grade John F. Kennedy in 1943. On the night of August 1, 1943, the boat, in company with others from its squadron, was operating in the Solomon Islands in an area called the Blackett Strait. In a confused action with Japanese destroyers, during which the American torpedoes exhibited failures with their detonators, PT 109 was separated from the rest of the squadron. The boat was idling to prevent it from creating a wake (visible to patrolling aircraft) when a Japanese destroyer bore down on it.

With less than ten seconds to react, bring the boat underway, and evade, the boat was doomed. The destroyer rammed the wooden vessel, slicing it in half, and setting it afire. After remaining with the drifting forward section for a time, Kennedy led the survivors on a swim to Plum Island, 3.5 miles away, with Kennedy towing one badly injured man despite being injured himself. Kennedy’s actions in the aftermath of the sinking of his boat made him a war hero. The boat itself, or rather what remained of it, drifted out of sight as the men swam away, and was not seen again by any of them.

22. Ballard’s expedition found the wreckage of PT 109 in 2002

The search for the remains of PT 109 presented difficulties and challenges far different from those of Titanic, Yorktown, and Bismarck. The search area was much smaller than those in the open sea. The depth of the waters to be searched was also much shallower. But the amount of wreckage and debris in the area was large, due to the many sea and air battles which had raged in the area during the war. There was also the problem of not knowing where the vessel had sunk, since it was last known to be adrift, without power, subject to the whims of nature. It was also in two pieces, with the stern section having sunk an unknown distance from the bow, and also in an uncertain location.

Data provided by the Navy allowed Ballard to focus his search in an area of roughly five by seven miles. The shifting sea floor obscured many targets while others found and examined were revealed to be other wreckage from the war. On May 22, 2002, the expedition discovered a torpedo tube and a torpedo, photos of which were sent to the US Navy for examination. After confirming that the tube and a cranking mechanism used to angle it outboard for firing were from a World War II PT boat the Navy examined its historical records and learned that no other such boats had been lost in the area. The Navy confirmed that the remains were the wreckage of PT 109’s forward section, and the site was treated as a war grave. The remains of the stern section have yet to be found.

23. US Navy operations in conjunction with undersea searches benefits both

The classified participation of the US Navy covered by the search for Titanic brought benefits to the science of undersea exploration and to the Navy’s understanding of how two of its submarines were lost. Items were recovered from the site of USS Thresher which confirmed much of what the Navy already suspected regarding the tragedy which cost 129 men their lives. Whether anything was recovered from the wreck of Scorpion remains classified, but the data obtained in the case of both sunken submarines ensured that they are having no adverse effect on the environment, and their nuclear reactors and weapons remain safe.

Both search techniques and capabilities were improved, for both the Navy and the ocean research community. The techniques developed have been used, and will continue to be used and improved, in the search for aircraft lost at sea, both commercial and military. They have helped the Navy locate lost weapons, map the sea bottom, and locate undersea cables and hazards. Deep submergence photography which sends back ghostly images of long-lost ships has other military applications used by the Navy to enhance its capabilities. The search for Titanic was not the first seemingly civilian operation that was actually a secret military exercise, nor will it be the last, as long as there is discernible mutual benefit.

Where do we find this stuff? Here are our sources:

“USS Thresher (SSN 593)” Article, Naval History and Heritage Command. Online

“Why They Called the Scorpion ‘Scrapiron'”. Mark A. Bradley, Proceedings, US Naval Institute. July, 1998

“Blind Man’s Bluff: The Untold Story of American Submarine Espionage”. Sherry Sontag, Christopher Drew. 1999

“Robert Ballard, American Oceanographer”. Entry, Encyclopedia Brittanica. Online

“Navy Indicates Cause of 1968 Sub Sinking”. UPI, The New York Times. December 17, 1984

“Titanic Was Found During Secret Cold War Navy Mission”. John Roach, National Geographic. November 21, 2017

“Titanic discovery was part of a secret US military mission”. Eric Levenson, CNN. December 14, 2018. Online

“How the US Navy used the Titanic search as a Cold War coverup”. Staff, Irish Central. December 14, 2018. Online

“The Discovery of the Titanic”. Robert D. Ballard. 1987

“Two Fallen Nuclear Submarines and their Top-Secret Link to the Titanic”. Erik Ofgang, Connecticut Magazine. April 17, 2019

“The discovery of the Titanic Wreck was a front for a secret US military mission”. Natasha Frost. QZ.com. December 18, 2018

“Exploring the Titanic”. Robert D. Ballard. 1988

“A review of significant salvage operations conducted by US Navy salvage forces and other salvage activities during 1969”. Naval Ships System Command. Archived. Online

“An eyewitness account of the sinking of the Bismarck – Archive”. The Guardian. May 31, 2016

“The Discovery of the Bismarck”. Robert D. Ballard. 1990

“Nazi Crew, Not British Fire, Sank The Bismarck, Explorer Believes”. Annie Tin, Chicago Tribune. June 23, 1989

“Shattered Sword: The Untold Story of the Battle of Midway”. Jonathan Parshall, Anthony Tully. 2005

“Lost ship is lost no more; National Geographic expedition finds Yorktown”. Randolph E. Schmid, Associated Press. June 8, 1998

“Remembering PT 109”. Owen Edwards, Smithsonian Magazine. November 2010

“Collision with History: The Search for John F. Kennedy’s PT 109”. Robert D. Ballard. 2002

“Why We Must Explore the Sea”. Robert D. Ballard, Smithsonian Magazine. October, 2014