USS Johnston (DD-557) in the context of "Destroyer escort"

Limiting Factor, known as Bakunawa since its sale in 2022, and designated Triton 36000/2 by its manufacturer, is a crewed deep-submergence vehicle (DSV) manufactured by Triton Submarines, built for and originally owned and operated (2018–2022) by explorer Victor Vescovo's ocean research firm, Caladan Oceanic, and currently owned and operated by Gabe Newell's Inkfish ocean-exploration research organization. It currently holds the records for the deepest crewed dives in all five oceans. Limiting Factor was commissioned by Victor Vescovo for $37 million and operated by his marine research organization, Caladan Oceanic, between 2018 and 2022. It is commercially certified by DNV for dives to full ocean depth, and is operated by a pilot, with facilities for an observer.

The vessel was used in the Five Deeps Expedition, becoming the first crewed submersible to reach the deepest point in all five oceans. Over 21 people have visited Challenger Deep, the deepest area on Earth, in the DSV. Limiting Factor was used to identify the wrecks of the destroyers USS Johnston at a depth of 6,469 m (21,224 ft), and USS Samuel B. Roberts at 6,865 m (22,523 ft), in the Philippine Trench, the deepest dives on wrecks. It has also been used for dives to the French submarine Minerve (S647) at about 2,350 m (7,710 ft) in the Mediterranean sea, and RMS Titanic at about 3,800 m (12,500 ft) in the Atlantic.

The Battle off Samar was the centermost action of the Battle of Leyte Gulf, one of the largest naval battles in history, which took place in the Philippine Sea off Samar Island, in the Philippines on October 25, 1944. It was the only major action in the larger battle in which the Americans were largely unprepared. After the previous day's fighting, the Imperial Japanese Navy's First Mobile Striking Force, under the command of Takeo Kurita, had suffered significant damage and appeared to be retreating westward. However, by the next morning, the Japanese force had turned around and resumed its advance toward Leyte Gulf. With Admiral William Halsey Jr. lured into taking his powerful Third Fleet north after a decoy fleet and the Seventh Fleet engaged to the south, the recently landed 130,000 men of the Sixth Army were left vulnerable to Japanese attack on Leyte.

Kurita, aboard the Japanese battleship Yamato, took his large force of battleships, cruisers and destroyers from the San Bernardino Strait and headed south toward Leyte, where they encountered Task Unit 77.4.3 ("Taffy 3"), the northernmost of the three escort carrier groups under Rear Admiral Clifton Sprague that comprised the only American forces remaining in the area. Composed of only six small escort carriers, three destroyers, and four destroyer escorts, Taffy 3 was intended to provide shore support and anti-submarine patrols, and did not have guns capable of penetrating the Japanese armor. The Japanese opened fire shortly after dawn, targeting Taffy 3's escort carriers, which Kurita mistook for the main carriers of the Third Fleet. The escort carriers fled for the cover of rain squalls and launched their aircraft in defense, while the three destroyers and destroyer escort USS Samuel B. Roberts, led by USS Johnston, launched a torpedo attack that sank one ship and sent the Japanese strike force into disarray.