United States Navy operations during World War I began on April 6, 1917, after the formal declaration of war on the German Empire. The United States Navy focused on countering enemy U-boats in the Atlantic Ocean and the Mediterranean Sea while convoying men and supplies to France and Italy. Because of United States's late entry into the war, her capital ships never engaged the German fleet and few decisive submarine actions occurred.Morison, pp. 861–865.
Operations Atlantic Ocean The main theater of World War I was the Western Front. In order to relieve the British and European allies already on the battle front, the United States Navy was tasked with transporting millions of U.S. soldiers and supplies across the Atlantic to France. The United States Navy was ill prepared for war, and the only solution was to begin deploying whatever was available on convoy duty and arming merchantmen with small naval guns manned by armed guard detachments.
Congress declared war on April 6, 1917, which meant the United States Coast Guard automatically became a part of the Department of the Navy. Destroyers and similar escort warships were considered the most effective means of sinking enemy submarines and protecting merchantmen. Therefore, destroyer squadrons were based in the British Isles at major ports, including Queenston, Ireland. The capital ships took up positions with the British Royal Navy in the North Sea for an uneventful blockade of the German High Seas Fleet that would last even after the armistice into 1919.Morison, pp. 863–865.
The first victory for the United States Navy took place in the Atlantic on October 15, 1917. The destroyer , commanded by Lieutenant Commander W. N. Vernon, encountered off Mine Head, Ireland. After chasing the U-boat for an hour, U-61 turned around and fired a single torpedo, which struck Cassin to port. Gunner's Mate First Class Osmond Ingram noticed the torpedo just before it struck and alarmed the K-gun crew, who began firing depth charges. Cassin was heavily damaged, but her crew kept her afloat and continued firing. Ingram was killed and later was to receive the Medal of Honor, while nine others were wounded. Cassin struck U-61s conning tower, which forced her crew to disengage and retreat."Cassin", DANFS, U.S. Navy Naval History and Heritage Command
On November 17, 1917, two destroyers became the first U.S. Navy ships to sink an enemy submarine. and were escorting convoy OQ-20 eastbound, when a lookout sighted the periscope of . The U-boat was forced to surface by depth charges and then defeated in a brief surface engagement. At least one shot from Nicholson struck the U-boat, killing two men and causing heavy damage. The thirty-nine survivors abandoned the sinking U-58 and were taken prisoner. Lieutenants Frank Berrien and Arthur S. Carpender both received the Navy Cross.
Four United States Navy ships were lost during World War I, only two by enemy action, though six merchant ships with armed guards aboard were also destroyed. The first combat loss was , a destroyer, which was sailing to Ireland in a zig-zag pattern with five other warships from Brest. On December 17, Kapitänleutnant Hans Rose of sighted the destroyer and attacked with a spread of torpedoes. One was sighted by the Americans, but despite taking evasive action, she was fatally damaged. Commander David W. Bagley ordered his crew to abandon ship, and as she sank the armed depth charges aboard began to detonate, adding to the already heavy casualties. Sixty-six of her crew were killed, and more injured; only thirty-eight survived. Jacob Jones was the first U.S. destroyer ever lost in battle, and she went down within eight minutes.Feuer, p. 21."Jacob Jones", DANFS, U.S. Navy Naval History and Heritage Command
The largest loss of life for the U.S. Navy during the war was on the collier in March 1918. She left Barbados on March 4, 1918 bound for Baltimore, Maryland, but was never seen again. She may have been sunk by a German U-boat, but it is more likely that she capsized because of the shifting of her cargo of coal. Cyclops was lost with 236 crew and passengers.
Three United States Army and navy transports, USAT , USAT and , received credit for defeating a U-boat on April 4, 1918. Sailing back to the United States from France, a U-boat surfaced at 11:45 and fired her torpedoes at the Mallory. Lookouts spotted the tracks, and the ship was able to evade the torpedo. The submarine was then spotted, and all three ships opened fire with their main guns, hitting the U-boat as it submerged. The Americans began dropping depth charges, but the unknown U-boat was not seen again.Gleaves, p. 168.
The auxiliary yacht twice engaged the on May 21 off the coast of Spain while escorting a British merchantman."Christabel", DANFS, U.S. Navy Naval History and Heritage Command That afternoon, an oil slick was spotted by Christabels crew, and later, the wake of the submarine was spotted. Depth charges were dropped, but the submarine escaped and returned to harass the convoy that night. At about 11:00 p.m., lookouts on Cristabel sighted a periscope and immediately maneuvered to fire depth charges. Several successive hits damaged the U-boat, but it escaped and had to cruise on the surface to Santander to prevent its sinking. The crew of UC-56 were interned by Spain, but the U-boat was scuttled rather than be handed over. During the action, a few depth charges became loose aboard Christabel, and at great personal risk Ensign Daniel Augustus Joseph Sullivan secured them, earning him the Medal of Honor.Lieutenant Commander Daniel A.J. Sullivan, USNRF, (1884–1941)", Online Library – People, U.S. Navy Naval History and Heritage Command
On June 6 attacked the British ocean liner about 400 miles east of the Bermudas. Twenty-two crewmen were lost, but the rest survived in the lifeboats. The U-boat remained in the area to use the lifeboats as bait for Allied ships. A few hours, later the auxiliary cruiser USS Von Steuben arrived and found the lifeboats. But before she reached them, a torpedo was spotted. Two guns opened fire, one on the incoming torpedo and the other on U-151s periscope. The cruiser also began evasive maneuvers and the torpedo missed her.
, under Richard Feldt, raided the port of Orleans, Massachusetts, on the morning of July 18. Feldt surfaced in the dark and positioned his boat off Nauset Beach. He then began shelling the civilian tugboat Perth Amboy and four wooden barges with his deck gun. All five targets were destroyed. A few shells missed and struck shore, becoming the first enemy shells on the continental United States since the 1846 Siege of Fort Texas at the beginning of the Mexican War. Nine Coast Guard Curtiss HS seaplanes spotted the U-boat and dropped bombs on her, but all failed to detonate.Larzelere, p 135
The following day, USS San Diego suffered an explosion while sailing from the Portsmouth Naval Yard to New York City. The armored cruiser was northeast of Fire Island when it was thought a torpedo struck her port side below the waterline at the engine room below. The damage prevented a water tight hatch from sealing and the engine room and fire room No. 9 both flooded in minutes. Captain Harley H. Christy was convinced he was under a U-boat attack and ordered his men to battle stations. They began firing at anything that even vaguely resembled a periscope. When it was clear the ship could not be saved, Captain Christy gave the order to abandon ship. Twenty-eight minutes after the explosion, San Diego slipped under the waves, taking six crewmen with her. There was later some controversy over the sinking, as no U-boat was reported in the area. Eventually, the sinking was blamed on a sea mine possibly laid by U-156. USS San Diego was the only U.S. Navy capital ship lost in the war.
The only lightvessel of the lost in combat was Diamond Shoal Lightship No. 71. On August 6, she was patrolling off North Carolina's Diamond Shoals when she encounter a sinking cargo ship, Merak, a victim of .
The survivors were rescued, and LV-71s captain, Master Walter Barnett, sent out a warning to friendly that a U-boat was in the area."U-140" intercepted the message and returned. Upon arrival, she surfaced and Commander Waldemar Kophamel demanded the Americans abandon the lightship. As LV-71 was unarmed, her crew had no choice but to row ashore in their boat, while the U-boat destroyed ship with its deck gun. There were no casualties on either side.Messimer, p. 124.
USS Mount Vernon was a German ocean liner that was seized and armed by the United States Navy. On the morning of September 5, 1918, Mount Vernon was off the coast of France accompanied by four destroyers, when the periscope of was sighted. The auxiliary cruiser immediately opened fire with her main guns, damaging the submarine. However, U-82 managed to fire a torpedo. Mount Vernon tried to dodge the torpedo, but was unsuccessful. Thirty six sailors were killed and thirteen wounded, but the ship was saved. , , and all dropped depth charges, but the U-boat got away.
Tampa, Dictionary of American Naval Fighting Ships, U.S. Navy Naval History & Heritage Command
Operating as part of the U.S. Navy on 26 September 1918, parted company with convoy HG 107, which she had just escorted into the Irish Sea from Gibraltar. Ordered to put into Milford Haven, Wales, she proceeded independently toward her destination.Larzelere, p. 47 At 1930 that evening, as she transited the Bristol Channel, the warship was spotted by . According to the submarine war diary entry, the U-boat dived and maneuvered into an attack position, firing one torpedo out of the stern tube at 2015 from a range of about . Minutes later, the torpedo hit Tampa and exploded portside amidships, throwing up a huge, luminous column of water.Johnson, p. 55 The cutter sank with all hands: 111 U.S Coast Guardsmen, 4 U.S. Navy sailors, and 16 passengers consisting of 11 British Navy personnel and 5 civilians.Larzelere, p 49 She sank in the Bristol Channel at roughly . Alerted by the convoy flagship, whose radio operator reported having felt the shock of an underwater explosion at about 2045, search and rescue efforts over the succeeding three days turned up only some wreckage, clearly identified as coming from Tampa, and a single unidentified body. Three bodies were later recovered, two from a beach near Lamphey, Wales, and the other at sea by a British patrol boat. Tampa was identified as the largest loss of life suffered by a combatant ship during World War I.Larzelere, p 50
North Sea To support the North Sea Mine Barrage, the United States manufactured 100,000 naval mines to prevent U-boats from reaching Atlantic shipping lanes. The Barrage was implemented with the encouragement of then-Assistant Secretary of the Navy Franklin D. Roosevelt. Rear Admiral Joseph Strauss commanded a United States North Sea Mine Force mission of 10 minelayers to lay the mines. Over the next five months the US Navy laid 56,571 mines of the total 70,177 planted during the Barrage.
Rear Admiral Lewis Clinton-Baker, commanding the Royal Navy minelaying force at the time, described the barrage as the "biggest mine planting stunt in the world's history." The official statistics on lost German submarines compiled on March 1, 1919 credited the North Sea mine barrage with the certain destruction of four U-boats, probable destruction of two more, and possible destruction of another two.Belknap, Reginald Rowan The Yankee mining squadron; or, Laying the North Sea mining barrage (1920) United States Naval Institute pp.5,15,18-22,27-36,43-47,56,82-83,101&108