A German U-boat engages a target during the campaign in the Atlantic. One unfortunate consequence of deck guns was to reduce underwater performance.

U-boats alongside a depot ship in Kiel in 1913: (left to right) U.12, U.7, U. W and U.6. The Germany Navy’s U-boat designs steadily improved during the war.

“The United States Naval Air Force, Foreign Service, executed 30 attacks against enemy submarines, of which ten were considered to have been at least partially successful; it dropped 100 tons of high explosives on enemy objectives, and it had to its credit a total of 22,000 flights in the course of which it patrolled more than 800,000 nautical miles of submarine infested areas. In point of fact, it did immeasurably more than this, for these figures are very far from being a just or fair method of appraising the value of aircraft in naval warfare. I say this because almost always the damage inflicted by aircraft, when operating against surface craft, was of a contributory and indirect nature—the seaplane summoned destroyers to the scene of action and the submarine was destroyed’ describes what is meant by ‘indirect’ in this sense. The destroyers almost always got the credit, wherein the aircraft, the indirect destructive agency, was really responsible for bringing about the action in which the submarine was destroyed.”

So spake LCdr. W. Atlee Edwards, former aid for aviation on the staff of Admiral W. S. Sims, testifying before the Lampert Committee in 1925.

The primary role of Naval Aviation in WW I was antisubmarine warfare. The first recorded attack on an enemy submarine by a U.S. Naval Aviator was made by Ens. John F. McNamara on March 25, 1918, while serving at the Royal Navy Air Station, Portland, England. Although his attack was successful enough to warrant special commendations from the Secretary of the Navy and Adm. Sims, the later evaluation was “possibly damaged.”

The first attack from a U.S. Naval Air Station was from Ile Tudy, France, which, perhaps because of its location, had more antisubmarine action than any of our overseas stations. Two coastal convoys passed through its sector daily, one bound north, the other south. Around Penmarch Point, the water was deep near shore, free of reefs and sand bars and ideally suited to submarine operations. A majority of the “allos” received at Ile Tudy were from this area.

The operating routine was described by the station historian. “The sector was marked off into 25-mile squares, subdivided into squares of five miles. By this means planes were able to report position every half hour and be quickly and accurately located. Communication was maintained with shore bases by radio and pigeons, and with vessels by message buoys, phosphorous buoys, Very pistols and the blinker system. . . .

“A section of two planes escorted each convoy. As the sector was too long to be covered entirely by two planes, it was necessary to send out another section to relieve the first, when the convoy was approximately halfway through the area. This necessitated using at least eight planes per day for convoy work alone. In addition, there was always a section known as the ‘Alert’ ready to take the air from daybreak to dark in response to any ‘allos’ received. When the convoy was picked up, the planes would first circle over it. Then while one plane would remain around the convoy the other would fly as far as 10 to 15 miles ahead, zigzagging broadly on both sides. This plane would return, again circle the convoy, repeating the same maneuver again and again. Before leaving a convoy, the planes circled a last time in its neighborhood. In this way the convoy was well protected from surprise.”

On April 23, 1918, a convoy escort of two Donnet-Denhaut seaplanes, piloted by Ens. K. R. Smith and R. H. Harrell, QM1c, saw the first action. They joined the southbound convoy of about 20 ships, approximately six miles north of Penmarch Point. As the weather was very foggy, they first flew to the rear of the convoy to look for stragglers, then flew a wide circle toward the main body. Shortly after, they sighted a suspicious wake, apparently being made by a submarine moving at good speed, and went in to attack. Smith dropped two bombs, the first landing on the fore part of the wake and the second ten feet ahead. The explosions created a heavy disturbance in the water followed by many air bubbles and appeared so successful that Harrell did not drop his bombs. Instead, he marked the spot with a phosphorous buoy and circled. Smith then flew to a destroyer, USS Stewart, and dropped a message buoy. Stewart arrived in the target area, followed soon after by the French gunboat Ardente, and dropped three depth charges. The pilots circling overhead saw small pieces of wreckage, particles of sea growth and large quantities of oil coming to the surface, and shortly after returned to their base. The oil was still visible from the air as late as the sixth of May. Ens. Smith and his observer, Chief O. E. Williams, were officially credited by the French naval authorities with a submarine, were cited in the Order of the Day and awarded Croix de Guerre with Palm.

The North Sea coast of England, where NAS KILLINGHOLME was located, was also a favorite sub-hunting ground. In the month before the station was under U.S. command, Ens. J. J. Schieffelin attacked a submarine which, possibly because of damage, surfaced after he left the scene and was sunk by gunfire from British destroyers. Ten days later he was again in action. While he was en route to the Whitby area, extremely rough air over Flamborough Head bounced his plane so hard that one of the suspending bomb hooks was bent and he was forced to jettison half his bomb load. Off Whitby, he sighted a surfaced submarine and attacked. His one bomb exploded under the stern of the submarine, kicking it clear of the water and exposing its rotating screw to view. The sub then disappeared under water at a steep angle. Later that day, after he had directed surface craft to the position, a submarine surfaced in the general area only to be rammed and sunk by the destroyer HMS Garry. There was initial confusion over whether this submarine was the one attacked by Schieffelin, but later information confirmed that his submarine returned to base in damaged condition. The evaluation of both attacks was “probably seriously damaged.”

NAS LOUGH FOYLE in Northern Ireland, which guarded the north entrance to the Irish Sea, made its first attack October 19, 1918. Ens. George S. Montgomery, in seaplane LF-4, was escorting a 32-ship convoy when he sighted and successfully bombed a submarine apparently moving into position for an attack. Both bombs functioned, one striking 30 feet to the right of the periscope and the other ten feet forward. The assessment was “probably damaged” and the station history reported that “undoubtedly at least one ship in the convoy was saved by the timely bombing.”

Submarines did not always react passively to these attacks. On at least one occasion against a seaplane and once against an airship, the U-boats fought back. On August 13, 1918, four seaplanes, one piloted by Ens. J. F. Carson, left NAS DUNKIRK o n patrol. A short distance off the coast, a large submarine was sighted proceeding on the surface at high speed. Since it carried no identification marks, Carson fired a challenging signal. At that point, the submarine apparently spotted the planes and opened fire with its four-inch gun. Five shots were fired, three passing close to Carson’s plane, and several pieces of shrapnel pierced his fuselage and wings. Carson immediately returned fire with his machine guns and moved into bombing position. The submarine cleared the deck and dived. As she went down, Carson dropped two bombs, one exploding in the swirl and the second slightly forward of it. The submarine reappeared, her bow projecting from the water at a sharp angle. Within four minutes she again submerged, sliding stern first under water. Carson was credited with a sinking by the French government and awarded the Croix de Guerre.

The airship involved was the AT-13 out of NAS PAIMBOEUF. On October 1, 1918, after escorting one convoy through the area, the airship turned to meet another. On the way, she fired two shots on a rock for target practice. On the second shot the firing spring broke, putting her only gun out of action and reducing her offensive capability to bombs. At about two-thirty, the convoy was picked up and the airship made the usual circle overhead. Then, as two storms were observed approaching from the north and northeast, the airship took a heading to pass between them. Shortly after, a suspicious object sighted to the north was investigated. While still a mile away, it was made out to be a submarine and when it opened fire there was no doubt that it was enemy. Thirteen shells burst near the airship but none struck her. The airship took up the chase to get into bombing position but the head wind was so strong that the submarine could not be overtaken. Signals by radio and Aldis lamp informed the convoy of the situation and the chase continued until the submarine disappeared in the darkness.

Action against the U-boat was not confined to overseas waters. On a Sunday morning, July 21, 1918, the U-156 surfaced off Nauset Beach, Cape Cod, and began what has since been called the Battle of Chatham. It was tersely reported in the weekly Aviation Bulletin as: “Sunday morning off Chatham, German submarine of the latest type appeared. She had two 6-inch guns with which she shelled and sank some barges. Seaplanes were sent out and submarine submerged.” There was more to it. Details were reported by dispatch and telephone. The gist of it was that an enemy submarine was reported at 10:10, three miles off Coast Guard Station 50. Four minutes later, an HS-2, piloted by Ens. Eric Lingard, left the station, flew over the submarine at 400 feet and dropped a bomb which failed to explode. At 11:15, the C.O. of the station, Lt. Philip Eaton, USCG, took off in an R-9, reached the scene a few minutes later and bombed from 500 feet. The bomb hit about 100 feet off the starboard quarter. It too failed to explode. After firing four shots at the seaplanes, the sub submerged and was lost in thick smoke.

These are but a few of the 30 attacks reported by LCdr. Edwards. The evaluation of results was difficult, even as it was in a later war. The appearance of oil and sea growth on the surface after an attack was a common feature of reports in both wars. Then, as later, early assessments leaned toward the optimistic; post-war records gave the hard, cold facts. But more important than confirmed destruction was the extent to which Naval Aviators met the challenge of their first test in combat and presented a real threat to submarine commanders and kept them from their appointed tasks.