Vice Admiral Morton Lyndholm Deyo (1 July 1887 – 10 November 1973) was an officer in the United States Navy, who was a naval gunfire support task force commander of World War II.

Born on 1 July 1887 in Poughkeepsie, New York, he graduated from the United States Naval Academy in 1911, and served over a career of 38 years. His classmates at the Naval Academy included Harry W. Hill, Frank J. Lowry, George D. Murray, John W. Reeves, and Frederick L. Riefkohl. His highest Navy rank in active service was rear admiral, attaining vice admiral at retirement. He was awarded three medals of personal honor, the Distinguished Service Medal (Navy), and the Legion of Merit with Gold Star.USS Deyo webpage. DD-989 USS Deyo ship's history. Viewed 08/08/2011.

Deyo served in both the Atlantic and Pacific Fleets. In the Atlantic, he commanded the destroyers which provided the first American escort assistance to allied convoys to England just prior to the Japanese attack on Pearl Harbor. He later commanded naval gunfire support at Utah Beach in the Normandy invasion, Task Force 129 at the bombardment of Cherbourg, as well as during the invasion of Southern France.

When transferred to the Pacific, Rear Admiral Deyo assumed command of Cruiser Division 13 (CruDiv 13). He commanded gunfire and covering force for the assault and occupation of Battle of Okinawa. During the battle, he was the last naval commander to form a battle line with battleships as they prepared to intercept the . At the war's end, he accepted the surrender of Japanese forces at Sasebo, Kyushu and directed the Allied Occupation of Western Japan.

Early career

Morton Deyo's career ashore meshed with the seagoing responsibilities he would take on at each stage of his career. Training at the U.S. Naval Academy prepared him in engineering and seamanship. He graduated as a member of the Class of 1911. Most of his academy years were under Superintendent Captain John M. Bowyer at a time of two-year rotations.U.S. Naval Academy. About Us: Superintendents Up-to-date listing of U.S. Naval Academy Superintendents. Viewed August 22, 2011. Deyo then took his first assignment at sea aboard the battleship .

Caribbean service

Early assignments at sea placed Deyo in the Caribbean. He was aboard the battleship about the time she participated in coaling-at-sea operations. In the years of his service aboard Virginia, she took station off Tampico and Vera Cruz, Mexico.Dictionary of American Naval Fighting Ships, Washington-VII Deyo next served aboard the destroyer . In a tour cut short by decommissioning in 1914, Duncan went to the Caribbean for training, target practice and exercises.Dictionary of American Naval Fighting Ships, commissioned 30 Aug 1913|| Duncan-I In 1914 and 1915, Deyo served aboard the armored cruiser under Captain Edward W. Eberle, commanding. The ship was stationed off of Santo Domingo, Dominican Republic, for diplomatic service; Vera Cruz, Mexico; Cap Haitien, Haiti; and returned to Puerto Plata, Dominican Republic, when a crisis recurred there.Dictionary of American Naval Fighting Ships, Washington-VII Deyo's last tour in the Caribbean before marriage and World War I was aboard the destroyer . She sailed to Tampico, Mexico and later supported the U.S. occupation of Vera Cruz. Jenkins was assigned patrol operations to search for possible German U-boats.Dictionary of American Naval Fighting Ships, Jenkins-I Deyo married Maria Ten Eyck Decatur Mayo in 1916.

As an aide to the Commandant, First Naval District, Boston, 1920–1921, Deyo was a part of an ongoing upgrading of the Naval District that would remain in place from 1920 to the outbreak of World War II. The First District absorbed the Second in 1919, and it expanded from a coastal strip to encompass inland states to more nearly correspond to Army districts. The District acquired its own full-time staff, gained new operational functions, and expanded administrative and logistical responsibilities. Proposal for reform of the Naval district regulations were to be revised to embody the lessons of World War I. This is fundamental naval strategy. Mahan had written, "deficient coast protection reacts unfavorably upon the war fleet, which in all its movements should be free from any responsibility for the mere safety of the ports it quits."Department of the Navy – Naval Historical Center. Fifty Years of Naval District Development 1903–1953, The Navy Department Library webpage, viewed 08/17/2011. Deyo's next assignment was as an aide to the U.S. military governor at Santo Domingo, Dominican Republic.

Service aboard one ship and command of another prepared Deyo for duty ashore in a politically and diplomatically sensitive role. In 1914–1915, Deyo had served on the armored cruiser during service related to Santo Domingo, Dominican Republic, Vera Cruz, Mexico, and Cape Haitien, Haiti. Capt. Edward W. Eberle, commanding, was active in U.S. attempts to mediate between government and insurgent forces towards a constitutional government with "observed" elections.Dictionary of American Naval Fighting Ships, Washington-VII When then Lieutenant Commander Deyo had his first command, of the destroyer , he was attached to the "Adriatic Detachment" performing political and diplomatic duties among nations of the former Austro-Hungarian Empire.Dictionary of American Naval Fighting Ships, Morris-VI In 1921–1923, Deyo served on the staff of the military governor closing out the American occupation of Santo Domingo. The military governor at the time was Warren Harding's appointment to fulfill his campaign promise to end the Wilson occupation of the Dominican Republic. Rear Adm. Samuel Robison served from 1921. The occupation officially ended July 1, 1924.Pons, Frank Moya., The Dominican Republic: a national history. In 1923 Deyo was assigned to the staff Battleship Fleet, aboard the battleship .

World War I

As a part of the new full-time staff in the First Naval District, Boston, in 1918, Deyo taught destroyer seamanship. He was assigned the year after Rear Admiral Albert Gleaves, then Commander, Destroyer Force, Atlantic Fleet, became Commander of United States Convoy Operations in the Atlantic in addition to his other duties.Gill, Charles C., U.S. Transport Service in the World War reprinted at First World War website, viewed August 18, 2011. He was next transferred to the troopship Northern Pacific as a part of its regular USN officer complement. World War I's movement of a million men and their supplies was unprecedented. The crews of harbor and pilot boats, inshore scouts and patrol craft, new merchantmen, escorting vessels, all required training.Department of the Navy – Naval Historical Center. Fifty Years of Naval District Development 1903–1953, The Navy Department Library webpage, viewed 08/17/2011. In the First Naval District, Deyo was a part of the destroyer piece.

Interwar

1920s Pacific

Deyo was attached to Admiral Samuel Robison's personal staff of ten officers aboard the in 1925–1926. Now a lieutenant commander, Deyo was the most junior officer as flag lieutenant. The next rung up the ladder was the Assistant Chief of Staff, then Commander Chester W. Nimitz.Naval Historical Center, Photo of Admiral Samuel S. Robison, USN, and staff, 1926 Commander-in-Chief, United States Fleet. Members of his personal staff aboard the Fleet flagship, USS Seattle (CA-11), Commencement Bay, Tacoma, Washington, 28 July 1926.

Following early armored cruiser service in the Caribbean,Dictionary of American Naval Fighting Ships, Washington VII World War I destroyer service operating in the North Atlantic,Dictionary of American Naval Fighting Ships, Allen-II and cruiser service crossing the Pacific,Dictionary of American Naval Fighting Ships, Seattle-I Deyo was assigned to a three-year tour teaching seamanship at the Naval Academy, 1926–1929. He was appointed during the tenure of Superintendent Rear Admiral Louis M. Nulton and completed his tour under Rear Admiral Samuel S. Robison with whom he had served in the Dominican Republic.U.S. Naval Academy. About Us: Superintendents Up-to-date listing of U.S. Naval Academy Superintendents. Viewed August 22, 2011. He returned to sea to take command of the destroyer .

His exemplary promise as a commander at sea resulted in an appointment to the Naval War College staff immediately following his study there. He then returned to sea in 1934 as the executive officer aboard the light cruiser .

1930s Pacific

World War II in the Atlantic

With accumulating experience in escort service in the Atlantic, fleet staff service crossing the Pacific, and Asiatic Squadron staff duty for operations and war plans during Japanese expansion, Deyo was prepared for Main Navy assignments from 1939 to 1941 as the Navy's assistant hydrographer, then aide to the Secretary of the Navy until war sent him to sea again.

Then a captain, Deyo was escort commander of Task Unit 4.1.1 and the Commodore of Destroyer Squadron 11.Cressman, Robert. The official chronology of the U.S. Navy in World War II Naval Institute Press. 1999. , p.51 His group was tasked to escort 44 merchant ships ranging from a luxury liner to a rusty ship of the Levant. His pennant and the were the only modern destroyers in the group. The others were "four-pipers" with "outmoded equipment and low fuel capacity" including the ships of two other squadron commanders.The destroyers in the Task Unit 4.1.1 were Ericsson (pennant comdesron 11), Eberle, Dallas, Upsher (pennant comdesron 30), Upshur, Ellis (pennant comdesron 60). The official designation of the Convoy was HX 150. (Roscoe, 1953, p.35) Ericsson DD440, Eberle DD430, Ellis DD154, Dallas DD199 and Upshur DD144. On Thursday, 18 September 1941 it assumed escort duties for convoy HX 150, 150 miles south of Newfoundland (Cressman, 1999, p.51 Canadian escorts protected the convoy for the first 350 miles, then the Americans until point "Momp" when the British escorted ships to Britain. Deyo then proceeded with the American destroyers to Iceland with three American merchantmen and one Icelandic.Roscoe, Theodore. United States destroyer operations in World War II, 1953 U.S. Naval Institute , p.35.

There was no submarine attack, but the Navy destroyers were inexperienced in their seamanship. They progressed from patrolling only on calm moonlit nights within 1,000 yards of the convoy and staying on station if there was fog, to patrolling 5,000 yards out whatever the sea condition or visibility. U-boat searches were extended to over an hour at a time. Still there was extra work to escorting this convoy. Stragglers, breakdowns and laggards created a ragged formation which was difficult to cordon. The convoy could not sit in the water, so it made numerous course changes to buy time for at-sea overhaul of those falling behind. Nevertheless, when the Nigaristan sank in high winds and rolling seas, the Eberle rescued the entire 63-man crew. On return to the U.S., "Captain Deyo made a number of adversely critical comments in his report" relative to the demands of anti-submarine warfare, "leadership, seamanship and marksmanship."Roscoe, Theodore. op.cit., p. 35.

On 6 June 1944, now Rear Admiral Deyo commanded the western Operation Neptune Force "U", supporting the landing of the American First Army at Utah and Omaha beaches during the Normandy landings.USS Deyo webpage, op.cit.

Deyo served as Commander, Task Force 129 (CTF 129) during the bombardment of Cherbourg, and supported General J. Lawton Collins's Army VII Corps in taking Cherbourg, France. The American and British ships dueled port-city shore batteries and surrounding German defenses. The battleship and destroyers , , and were all damaged by enemy fire.Crossman, op.cit., p. 238

Deyo commanded the naval bombardment for the invasion of Southern France in August 1944 and received Legion of Honour, Officer by the Government of France.USS Deyo webpage, op.cit.

World War II in the Pacific