Underwater Demolition Team # 12 was formed at Naval Combat Demolition Unit, Amphibious Training Base, Fort Pierce, Florida. The eighty (80) men and fifteen (15) officers making up the complement of the team had been trained in class Seven and Eight with replacements from the training staff and former classes who had not been previously assigned. On September 26, 1944, Lt. Commander E. S. HOCHULI, USNR, was assigned as Commanding Officer.

The team left Fort Pierce, Florida on 30 September 1944 on a troop train bound for San Bruno, California for further transfer outside the continental Limits of the United States. Teams # 11 and # 13 accompanied. Enroute to the west coast orders were received changing the destination to Camp Shoemaker and the team spent two days there drawing overseas gear before reporting to Treasure Island for embarkation. Orders to report aboard the USS GENERAL PATRICK were received and the team embarked and left San Francisco on 14 October 1944.


Proceeding via Pearl Harbor, Team # 12 reported at Naval Combat Demolition Training and Experimental Base, Maui, T.H., for advance demolition training on 22 October 1944. From 1 November to 1 January 1945 the team underwent  reorganization with many personnel changes. Swimming and physical instruction as well as advance training in demolition and reconnaissance was carried on day and night with emphasis on APD training problems. The complement was filled with thirteen (13) officers and eighty-five (85) enlisted men.

On January 7, 1945 the team was ordered aboard the USS BATES (APD 47) and departed Maui for Pearl Harbor. Here explosives and team gear were taken aboard and the ship provisioned. Team # 13 accompanied on the USS BARR (APD 39). Together with the USS NEVADA and an AGC the ships left Pearl Harbor bound for Ulithi, staging area for the Iwo Jima operation.

On 10 February 1945 after intense rehearsals Underwater Demolition Teams # 12, # 13, # 14 and # 15 left Ulithi together with transports and ships of the fleet. The advance group arrived off Iwo Jima on 16 February 1945 and the APD’s circled the island at 2500 yards that date making observations to aid in final operation planning.

The Underwater Demolition Teams under command of Commander Underwater Demolition Teams, Amphibious Forces, Pacific Fleet, Captain B. HALL HANLON, USN, was assigned the task of making reconnaissance missions on the eastern beaches at 1100 and on the western beaches at 1630 on 17 February 1945 (D-2). Team # 12 conducted reconnaissance of Red 1 and 2 beaches (1000 yards) on the eastern side and Brown 1 and 2 beaches on the western side. Swimmers were dropped from LCPR's 500 yards from the beaches with pairs of swimmers covering approximately 100 yards of shore line before returning to be picked up by the LCPR's. Swimmers were equipped with mine detonating devices and made careful observations of the approaches and shore line. The information was prepared in the form of charts and dispatches and turned in to higher authority to be relayed to the approaching landing force.

During the reconnaissance mission on the eastern beaches, the fire support ships LCI(G's) drew heavy machine gun, mortar and rifle fire which took a heavy toll of personnel manning the LCI's. One Underwater Demolition Team # 12 officer, Ensign Frank JIRKA, USNR, assigned as observer aboard the LCI(G) 466, lost both feet as the result of a mortar hit on the bridge. (Editor’s note: Ensign Frank Jirka was a swimmer. Click here to read his firsthand account of this life-changing event.) A.E. ANDERSON, CM 1c, a swimmer was listed as missing in action. On D-Day several officers from Underwater Demolition Team #12 led the first waves into Red beaches while other officers were assigned to Control Boats in an advisory capacity. From D+1 to D+9 Underwater Demolition Team #12 was assigned to the Senior Beachmaster and engaged in clearing the eastern landing beaches of wrecked craft, LCPR's, LCVP's LVT's, LCM's, pontoon barges, ect. The team was detached and departed the area D+3 heading for Ulithi via Guam.


At Ulithi the teams staged for the Okinawa Operation. Still embarked on the APD 47, Underwater Demolition Team # 12 in the advance group arrived off the Kerama Retto on 25 March 1945 and proceeded into the Retto to conduct three reconnaissance missions on Yakabi Shima, Zamami Shima, and Amuro Shima. The following day (L-6, 26 March 1945) officers and men served as pilots for the Army landing force (77th Division) which landed to secure the western islands as a fleet anchorage. On L-3 a demonstration reconnaissance was made on Green Able Beaches 1 and 2 on the southern coast of Okinawa. The following day a demonstration demolition job was carried out consisting of setting off charges at the reef’s edge. The purpose of the demonstration was to divert enemy troops from the main landing beaches. The USS BATES was assigned a screening station off Okinawa until 10 April 1945 (L+9): During this time the ship was attacked on several occasions by suicide planes but not hit. Twenty-one wounded survivors from a destroyer hit by Kamikaze planes were picked up and medical aid given by ships crew and Underwater Demolition Team personnel on 8 April 1945. On 10 April 1945 the BATES with Underwater Demolition Team # 12 departed the area returning to Ulithi via Saipan.


The team disembarked on 19 April 1945 taking explosives and team gear as well as personnel ashore on Asor Island, Ulithi, quarters were assigned in the receiving station and a program of rehabilitation and physical training with major emphasis on swimming was carried out. On 1 May 1945, Lt. Commander HOCHULI was ordered on temporary additional duty with the Seventh PhibForce and returned to Okinawa to represent Commander Underwater Demolition Teams, Amphibious Forces, Pacific Fleet during mop up operations on small islands near Okinawa. Lieutenant W.H. JONES, USNR, became acting Commanding Officer. During the month, R. P. PIERRE, COX, saved the life of a drowning man and was recommended for a citation.


Underwater Demolition Team # 12 together with Team # 7 and # 16 were ordered to return to the Demolition Base, Maui, T.H., and embarked on the SS JEAN LAFITTE, 6 JUNE 1945. The ship reached Pearl Harbor 23 June 1945 and the Team returned by LSM to Maui reporting 25 June 1945. On 1 July 1945, Lt. Commander HOCHULI, USNR, was detached from the Team to become Chief of Staff to Commander Underwater Demolition Squadron TWO. Lieutenant W.H. JONES, USNR, became Commanding Officer and Lt(jg) J.E. ABER, USNR, became Executive Officer.

Underwater Demolition Team # 12 was ordered to report to the Amphibious Training Base, Oceanside, California and embarked on the USS AMESBURY APD 46 on 16 July 1945. The team reported at the Amphibious Training Base, Oceanside, 23 July 1945 for cold water swimming and training which was to begin 15 August 1945 in preparation for the invasion of Japan. Proposed surrender by the Japanese and acceptance of the Potsdam Terms caused plans to be alerted and the entire Underwater Demolition Flotilla was ordered to proceed to Forward Areas to become part of the occupation forces.


(compiled by Robert Allan King for the UDT-SEAL Museum from public records at the Operational Archives of the Naval Historical Center)

TEAM ROSTERS - To protect the integrity of the Teams and the privacy of individual frogmen, Team rosters are not made public. If you or your relative was a member of UDT Team Twelve and you would like further information, we suggest you contact the UDT-SEAL Museum.

Ensign Frank Jirka’s story and Frank Jirka’s personal photo album of UDT 12 officers and men

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