Consolidated by U.S. Navy Seabee Museum, Naval History and Heritage Command
April 25
1945: ACORN 46 decommissioned and Naval Air Base Marpi Field, Saipan commissioned. (Used during World War II, an ACORN was a tailored unit designed to carry out the rapid construction and subsequent operation of a landplane and seaplane advance base. Each ACORN had a construction battalion attached to it, as well as trained personnel to operate the control tower, field lighting, aerological unit, transportation, medical, berthing, and messing facilities. A Construction Battalion Maintenance Unit (CBMU) also accompanied each ACORN to maintain the base after the initial construction was completed and the construction battalion had been withdrawn. During the war, ACORNs were sent to such places at Guadalcanal, Espiritu Santo, Green Island, Rendova, Treasury Island, and Majuro.)
1946: 93rd NCB inactivated at Samar, Philippines.
1965: As NMCB 10 prepared to mount out from Okinawa for the RVN, planning groups of two officers and three enlisted men from NMCB 9, and three officers and three enlisted men from NMCB 3, arrived at Danang to perform preliminary engineering and material procurement for Seabee projects then being programmed and scheduled for I Corps (ICTZ), Vietnam.
1967: NMCB 11 main body departed from Point Mugu Naval Air Station, California aboard MAC C-130 aircraft for Dong Ha Forward Combat Base, RVN.
April 26
1943: 9th Special NCB commissioned at Naval Construction Training Center (NCTC) Camp Peary, Magruder, Virginia.
1967: NMCB 11 main body consisting of 16 officers and 637 enlisted personnel deployed from CBC, Port Hueneme, California to the Dong Ha Forward Combat Base, RVN, via 11 Military Airlift Command C-130 aircraft.
1970: Seabee Team 0412 with Lt. j.g. J.A. Werner, Civil Engineer Corps (CEC) as Officer in Charge (OIC) departed CBC, Port Hueneme, California for training and indoctrination on Guam, before proceeding to their final deployment site on Koror Island, Palau District, TTPI.
1971: Seabee Team 4006 departed Davisville, Rhode Island for reassignment to OIC, Naval Construction Battalion, Pacific Fleet (CBPAC) Detachment (DET) RVN and deployment to Tan An, RVN.
April 27
1969: Disaster strikes area in and around ammunition supply point (ASP) 1, Da Nang when it erupted, as if it was a volcano. This was the largest ASP in I Corps area. NMCB 4 provided firefighting detail to assist NMCB 5. NMCB 5s Camp Hoover was adjacent to the huge ASP. NMCB 5s Camp Hoover was 90 percent destroyed; however, only two Seabees were wounded due to the immediate action taken during the initial explosions.
April 28
1943: 71st and 74th NCBs commissioned at Camp Peary, Magruder, Virginia.
1961: NMCB 9 was chosen to receive the first Peltier Award. Named in honor of Rear Admiral Eugene J. Peltier, a former Chief of the Bureau of Yards and Docks, the award is given annually to the most outstanding Seabee battalion. The Society of American Military Engineers presented the award, in association with the United States Navy.
1967: NMCB 11, the first battalion to be deployed to the Northern I Corps, commenced arriving at the Dong Ha Forward Combat Base, RVN.
1968: Lt. Cmdr. W.A. Simmons, CEC, relieved Cmdr. G.H. Brown, CEC, as executive officer, NMCB 71.
1971: NMCB 62 advance party, first and second flights, arrived at Camp Moscrip, Roosevelt Roads, Puerto Rico with 2 officers and 102 enlisted men.
1971: Seabee Team 0519 departed the continental United States (CONUS) enroute to the TTPI.
April 29
1965: NMCB 10 departed Okinawa via Navy ships (2 LSTs, 1 LSD, and 1 AKA) for Chu Lai, RVN.
1968: Seabee Team 1012 departed CBC Port Hueneme, California with 13 men for Thailand.
1971: NMCB 1 advance party departed Roosevelt Roads, Puerto Rico for Davisville, Rhode Island. Seabee Team 4005 departed Davisville, Rhode Island for reassignment to OIC CBPAC DET, Guam and deployment to Truk, TTPI.
April 30
1945: 44th Naval Construction Battalion (NCB) inactivated at Camp Parks, Shoemaker, California; 56th NCB inactivated on Guam.
1946: 134th NCB inactivated on Guam.
1968: Lt. Cmdr. W.A. Simmons, Civil Engineer Corps (CEC), relieved Cmdr. G.H. Brown, CEC, as executive officer of Naval Mobile Construction Battalion (NMCB) 71.
2004: In Anbar Province, Iraq, an improvised explosive device detonated and hit the vehicle carrying Equipment Operator 3rd Class Christopher M. Dickerson of Eastman, Georgia, and Hull Maintenance Technician 2nd Class Jason B. Dwelley of Apopka, Florida. Both men from NMCB 14 became the first Seabees killed in action since the Vietnam War.
May 1
1942: 3rd NCB commissioned.
1945: 33rd Naval Construction Regiment (NCR) inactivated; 33rd NCB inactivated at Peleliu; 57th NCB inactivated at Camp Parks, Shoemaker, California.
1946: 32nd Special NCB inactivated at Tsingtao, China.
1966: NMCB 4 at Chu Lai, Republic of Vietnam (RVN), began hiring and training of local Vietnamese laborers in the trades of carpenter, riggers, welder, mason, and automotive mechanics.
1970: Seabee Team 0314 returned to the continental U.S. (CONUS) via government aircraft.
1971: Headquarters of the 32nd NCB was moved from Vietnam to Roosevelt Road, Puerto Rico.