The windward region of Koʻolaupoko has long been considered the ‘bread basket’ of Oʻahu and highly favored with well-watered agricultural lands and verdant fishing grounds. (Sinoto)
Based on the oral traditions and legendary accounts, the Kaneʻohe Bay region was favored as a rich and productive agricultural, as well as marine resources area during the prehistoric period.
Dry land cultivation of such crops as sweet potato, yams, and breadfruit; wetland cultivation of taro; and aquaculture in the coastal fishponds and in the estuarine areas were practiced along with fishing in the near shore, lagoon and deep ocean zones. (Sinoto)
Mokapu ‘to separate by imposing a taboo’ is derived from the combination of two words, Mo is short for Moku (‘district or island’ and kapu ‘sacred, no trespassing, or keep out.’ If you entered a kapu district, you were killed.
Mokapu was named this because this is where King Kamehameha met with chiefs. The name of the meeting place was named ‘the sacred land of Kamehameha.’ (ksbe)
Mahinui, named for a legendary hero (translates as ‘great champion’ (Pukui) was known as a “regular place of rest for the travelers, called oioina by the ancients”. (Hoku Hawai‘i, 1925; Cultural Surveys)
The US military first established a presence on the Mokapu peninsula in 1918 when President Woodrow Wilson signed an executive order establishing Fort Kuwaʻaohe Military Reservation on 322-acres on the northeast side of Mokapu.
The army was responsible for the seacoast defense of Naval Air Station Kaneohe Bay, commissioned in 1939 on the Mokapu Peninsula. Permanent seacoast batteries were needed for long-term defense, while temporary defenses were necessary until the permanent defenses could be funded and constructed. (Bennett)
The Army stayed there until August 1940 when the Navy decided to acquire all of Mokapu Peninsula to expand Naval Air Station Kaneʻohe; it included a sea plane base, it began building in September 1939 and commissioned on February 15, 1941.
Between 1939 and 1943, large sections of Kāneʻohe Bay were dredged for the dual purposes of deepening the channel for a sea plane runway and extending the western coastline of the peninsula with 280-acres of coral fill.
On Sunday morning, December 7, 1941, two waves of Japanese Imperial Navy aircraft bombed and strafed Kaneʻohe Naval Air Station, several minutes before Pearl Harbor was attacked.
The bulk of the Harbor Defense facilities were equipped and deployed for a naval attack or amphibious landing; their defenses against an air attack failed to keep up with the magnitude of the aerial assault on December 7, 1941. (Williford)
Following the attack, to defend the military facility at Mokapu, a number of gun batteries were built. On June 14, 1942, authorization was given for installation of coast artillery armament for the defense of the Kaneohe Bay Air Station.
The battery site, and most others built on Oʻahu during World War II, was chosen for its field of fire coverage and ease and economy of construction. Preliminary reconnaissance of potential locations was made by the Corps of Engineers Design Division and the Hawaiian Seacoast Artillery Command. (Bennett)
In 1944, with two 8-inch guns, Battery 405 was built on the northeast lower slope of Puʻu Papaʻa, about 145- feet above sea level. The 542-foot peak is at the north terminus of the Oneawa Hills, on the dividing line between Kailua and Kaneʻohe.
Two tunnels were excavated into the hillside; each tunnel measured about 210-feet long by 10-feet wide, with 12-foot crowns, arched ceilings, and slab sidewalls. The walls and floors were concrete. The tunnels converged somewhat as they penetrated the hillside. (Bennett)
The guns were mounted in the open with no protection from bombardment, besides camouflage. The powder magazines, shell rooms, plotting room and support facilities were tunneled into the hillside.
The 8-inch guns did not have armored shields, leaving them and their crews vulnerable to enemy surface attack and even more to air attack. A metal lath structure resembling a farmhouse rooftop affixed to the carriage traversed with the guns, but only provided minimal camouflage. *Bennett)
Command and control functions were centered in the battery commander’s station above the gun emplacements, about the 300-foot elevation of Puʻu Papaʻa.
A single-story rectangular reinforced-concrete building dug into the ground was equipped with three narrow horizontal observation slots on the front and both side walls, with dropdown outside-hinged steel shutters. (Bennett)
Following the war (August 27, 1946,) Battery 405 was named Battery DeMerritt, after Robert E DeMerritt, a Colonel with the Coast Artillery Corps during World War II (he died in the “Line of Duty” of a non-battle related incident on July 25, 1942.)