USS Eversole (DE-404)

Laying the keel or laying down is the formal recognition of the start of a ship's construction. It is often marked with a ceremony attended by dignitaries from the shipbuilding company and the ultimate owners of the ship.

The Brown Shipbuilding Company was founded in Houston, Texas, in 1942 as a subsidiary of Brown and Root by brothers Herman and George R. Brown to build ships for the U.S. Navy during World War II. Brown Shipbuilding Company ranked 68th among United States corporations in the value of World War II military production contracts.

Houston is the most populous city in Texas and in the Southern United States. It is the fourth most populous city in the United States after New York City, Los Angeles and Chicago, and the sixth most populous city in North America. With a population of 2,304,580 in 2020, Houston is located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the seat and largest city of Harris County and the principal city of the Greater Houston metropolitan area, which is the fifth-most populous metropolitan statistical area in the United States and the second-most populous in Texas after Dallas–Fort Worth. Houston is the southeast anchor of the greater megaregion known as the Texas Triangle.

Texas is a state in the South Central region of the United States. At 268,596 square miles (695,660 km2), and with more than 30 million residents in 2022, it is the second-largest U.S. state by both area and population. Texas shares borders with the states of Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the west, and the Mexican states of Chihuahua, Coahuila, Nuevo León, and Tamaulipas to the south and southwest; and has a coastline with the Gulf of Mexico to the southeast.

Ceremonial ship launching involves the performance of ceremonies associated with the process of transferring a vessel to the water. It is a nautical tradition in many cultures, dating back thousands of years, to accompany the physical process with ceremonies which have been observed as public celebration and a solemn blessing, usually but not always, in association with the launch itself.

Boston, officially the City of Boston, is the capital and largest city of the Commonwealth of Massachusetts and the cultural and financial center of the New England region of the Northeastern United States. The city boundaries encompass an area of about 48.4 sq mi (125 km2) and a population of 675,647 as of 2020. The city is the economic and cultural anchor of a substantially larger metropolitan area known as Greater Boston, a metropolitan statistical area (MSA) home to a census-estimated 4.8 million people in 2016 and ranking as the tenth-largest MSA in the country. A broader combined statistical area (CSA), generally corresponding to the commuting area and including Worcester, Massachusetts and Providence, Rhode Island, is home to approximately 8.2 million people, making it the sixth most populous in the United States.

Pearl Harbor is an American lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. It was often visited by the Naval fleet of the United States, before it was acquired from the Hawaiian Kingdom by the U.S. with the signing of the Reciprocity Treaty of 1875. Much of the harbor and surrounding lands are now a United States Navy deep-water naval base. It is also the headquarters of the United States Pacific Fleet. The U.S. government first obtained exclusive use of the inlet and the right to maintain a repair and coaling station for ships here in 1887. The surprise attack by the Imperial Japanese Navy on December 7, 1941, led the United States to declare war on the Empire of Japan, making the attack on Pearl Harbor the immediate cause of the United States' entry into World War II.

A submarine is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as boats rather than ships irrespective of their size.

The Hawaiian Islands are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some 1,500 miles from the island of Hawaiʻi in the south to northernmost Kure Atoll. Formerly the group was known to Europeans and Americans as the Sandwich Islands, a name that James Cook chose in honor of the 4th Earl of Sandwich, the then First Lord of the Admiralty. Cook came across the islands by chance when crossing the Pacific Ocean on his Third Voyage in 1778, on board HMS Resolution; he was later killed on the islands on a return visit. The contemporary name of the islands, dating from the 1840s, is derived from the name of the largest island, Hawaiʻi Island.

Manus Island is part of Manus Province in northern Papua New Guinea and is the largest of the Admiralty Islands. It is the fifth-largest island in Papua New Guinea, with an area of 2,100 km2 (810 sq mi), measuring around 100 km × 30 km. Manus Island is covered in rugged jungles which can be broadly described as lowland tropical rain forest. The highest point on Manus Island is Mt. Dremsel, 718 metres (2,356 ft) above sea level at the centre of the south coast. Manus Island is volcanic in origin and probably broke through the ocean's surface in the late Miocene, 8 to 10 million years ago. The substrate of the island is either directly volcanic or from uplifted coral limestone.

Morotai Island is an island in the Halmahera group of eastern Indonesia's Maluku Islands (Moluccas). It is one of Indonesia's northernmost islands.

Leyte Gulf is a gulf in the Eastern Visayan region in the Philippines. The bay is part of the Philippine Sea of the Pacific Ocean, and is bounded by two islands; Samar in the north and Leyte in the west. On the south of the bay is Mindanao Island, separated from Leyte by the Surigao Strait. Dinagat Island partly encloses the gulf to the southeast, and the small Homonhon Island and Suluan Island, sit astride the eastern entrance to the Gulf. It is approximately 130 km (81 mi) north-south, and 60 km (37 mi) east-west.

The Battle of Leyte Gulf was the largest naval battle of World War II and by some criteria the largest naval battle in history, with over 200,000 naval personnel involved. It was fought in waters near the Philippine islands of Leyte, Samar, and Luzon from 23 to 26 October 1944 between combined American and Australian forces and the Imperial Japanese Navy (IJN), as part of the invasion of Leyte, which aimed to isolate Japan from the colonies that it had occupied in Southeast Asia, a vital source of industrial and oil supplies.

Sonar is a technique that uses sound propagation to navigate, measure distances (ranging), communicate with or detect objects on or under the surface of the water, such as other vessels.

A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such a device was called an automotive, automobile, locomotive, or fish torpedo; colloquially a fish. The term torpedo originally applied to a variety of devices, most of which would today be called mines. From about 1900, torpedo has been used strictly to designate a self-propelled underwater explosive device.

I-45 was an Imperial Japanese Navy Type B2 submarine. Completed and commissioned in December 1943, she served in World War II, patrolling in the Pacific Ocean and taking part in the Marianas campaign, the Philippines campaign, and the Battle of Leyte Gulf before she was sunk in October 1944.