The USS Dorado (SS-248) was a Gato-class World War II era submarine.
The namesake of the Dorado is also known as the dolphin fish or mahi-mahi.
Following her commissioning on August 28, 1943, the USS Dorado, captained by Lieutenant Commander Earle C. Schneider, sailed from New London on October 6, 1943, for duty in the Pacific via the Panama Canal. Her operation order directed her to maintain radio silence lest she be located by enemy submarines. Her prescribed course estimated she would complete her transit of the Mona Passage around 2:00 a.m. on October 12, 1943, and then head in a southwesterly direction to the U.S. Navy base at Coco Solo, Panama; her scheduled date of arrival there was October 14, 1943. She never made it to Panama nor was she heard from at any time after leaving New London. 1
Her loss was announced on October 24, 1943:
Navy Department Communiqué No. 476, October 24, 1943
1. The U. S. Submarine Dorado is overdue and must be presumed to be lost. The next of kin of personnel in the Dorado have been so informed.
There are several loss possibilities for the Dorado, however none of them provide sufficient evidence to support any definite conclusions.
1. The Dorado's loss is usually attributed to being depth charged on October 12, 1943, at 2051 hours, in the Caribbean Sea, at the geographic position 15° 31' N, 72° 37' W, by a U.S. Navy PBM-3 flying boat based at Guantanamo, Cuba. The aircraft had been assigned to provide protection for a friendly merchant convoy passing through the area that night, but had received incorrect information concerning the bombing restriction area surrounding the Dorado, which would also be sailing through that section of the Caribbean en route to Panama. The PBM-3 crew detected a surfaced submarine close to the merchant convoy at 2047 hours. They described the submarine as looking like a German mine laying U-boat. From 150 feet, they dropped three depth charges and one demolition bomb on the submarine; one depth charge and the bomb were duds, and no one aboard the aircraft saw or heard explosions from the remaining two depth charges. The aircraft made a second sweep and dropped flares to observe the results of their attack, but nothing was seen except a large patch of white water and bubbles; the pilot later said this was probably the swirl of water made by the sail of the submarine and its tanks being blown as the boat prepared to dive. About two hours later, they sighted a second surfaced submarine and attempted to exchange recognition signals with an Aldis lamp, but the boat commenced firing at the plane with its AA guns and took evasive action. The aircraft turned away to avoid the AA fire, and the submarine took cover in a rain squall and was not seen again. 2
In November 1943, a U.S. Navy Court of Inquiry found that it was highly probable that the Dorado was lost as a result of the attack by the PBM-3 flying boat, and that she either sank immediately or she was critically damaged, unable to communicate, and sank sometime later. It also found that not less than two of the depth charges dropped by the PBM-3 flying boat functioned as designed; crew aboard several of the convoy vessels had heard the report of and felt concussions from depth charges about the same time the PBM-3 flying boat had dropped its payload on the submarine. It was also noted that U.S. Navy surface vessels and aircraft had conducted an extensive search of the area of the attack and they did not find any survivors, wreckage, submarine debris, or oil slicks. 3
The Court of Inquiry called Commander Jack H. Lewis to testify as an expert witness in matters relevant to certain questions regarding submarines by reason of his experience as a submarine officer. He had served during the war as the Commanding Officer of the USS Trigger (SS-237) and the USS Swordfish (SS-193). At the time of his testimony he was the Prospective Commanding Officer of the USS Dragonet (SS-293). On November 9, 1943, the Court posed the following questions to Commander Lewis and he made the responses shown after each one.
"In the event that a submarine has been attacked by aircraft and the submarine has been materially damaged, do you think that any evidence of that damage would subsequently be shown on the surface even though the submarine itself disappeared after the attack?"
"I cannot conceive of a submarine being damaged to the extent that she is lost without very much evidence being left on the surface."
"What form would that evidence take?"
"Undoubtedly oil; and lots of it, would be on the surface. Also, wooden sections of the deck grating. If the pressure hull has been penetrated, and it, undoubtedly would be, there would be segments of cork floating to the surface. I, also, believe that for many hours afterwards there would be a lot of bubbles breaking the surface of the water." 4
At the end of World War II in Europe, the logbooks of German U-boats were reviewed and in September 1945 it was determined that the only German submarine operating in the Caribbean Sea at the time of the attack made by the PBM-3 flying boat was the U-214, a 600-ton mine laying U-boat. It was also determined that the U-214 was not the target of the PBM-3's attack. However, the U-214 was the submarine that fired at the PBM-3 with its AA guns. The U-214 had observed from a nearby position the flares dropped by the PBM-3, and proceeded to the area to investigate; this movement led to her sighting by the PBM-3. Thus the evidence implies the Dorado was the target of the PBM-3's attack. There was no evidence in the logbook of an attack by the U-214 on another submarine. 5
2. On October 8, 1943, the German submarine U-214 laid 15 mines near Colon, close to the entrance to the Panama Canal. The Dorado would have been in the vicinity of these mines shortly after they were planted, at a time when they posed the greatest hazard. The Dorado was possibly sunk by one of them. The first of these mines was not detected until October 16th. Over the next three weeks nine minesweepers cleared 10 mines. The rest of them were never found. 6
3. On the night of October 13-14, 1943, the German submarine U-214 laid two EMS mines east of the Antilles. It laid one EMS mine at 0025 hours, on October 13th, at 14° 57' N, 73° 21' W, and the other at 0420 hours on October 14th, at 14° 57' N, 71° 51' W. The EMS was a drifting mine. It floated on the surface and exploded on contact with a ship’s hull. It was armed 10 minutes after launching and was designed to stay afloat for 72 hours, after which it sank itself automatically. On October 15, 1944, between 1648 and 1707 hours, the U-214 documented hearing a heavy explosion followed by a series of eight more just like it. These multiple explosions could have been caused by contact with the mine by the Dorado. No other vessels were lost in this area at this time to explain the series of explosions. 7
4. The United States had planted numerous mines in the waterway leading to the Panama Canal off Cristobal to fend off enemy interlopers. Two types of mines were used there. Influence mines rested on the seabed and incorporated a pressure displacement fuse which would detonate when the hull of a vessel raised the ambient water pressure. Contact mines were moored to a concrete pad and floated above it albeit beneath the surface; they exploded when the hull of a ship hit them. A contact mine frequently loosed from its mooring and floated away with the prevailing current, thus endangering friendly shipping. There is a remote possibility the Dorado was destroyed by contact with one of these "floaters." 8
5. An operational loss is always possible. However, the Court of Inquiry found that "The USS Dorado sailed in excellent material condition, in a very good state of training for her projected operations, with a sufficient proportion of experienced officers and men; and that her commanding officer was above average in experience and ability in submarine operations." 9
6. The possibility of loss due to an unreported enemy attack is zero. Other U-boats operating in the general area during this time period were U-123, U-218, U-516, and U-518. Each of them returned safely to their home port, and none reported any attack on a submarine. In addition, none of them planted any mines. 10
A list of the personnel lost with Dorado is maintained at On Eternal Patrol.
1. United States Submarine Losses World War II, p. 63; Campbell, Douglas E., USS Dorado (SS-248): On Eternal Patrol, p. 17 and 43.
2. Miller, Vernon J., "U. S. Submarine Losses," issue 42, p. 120-122; Campbell, Douglas E., op. cit., p. 65-66.
3. Campbell, Douglas E., op. cit., 293-294 and 310-315.
4. Ibid., p. 299.
5. Ibid., p. 416-417.
6. Miller, Vernon J., op. cit., p. 120-122.
8. Campbell, Douglas E., op. cit., p. 35-36.
9. Ibid., p. 311.
10. Miller, Vernon J., op. cit., p. 120-122; "Patrols by U-123; "Patrols by U-218,"; "Patrols by U-516," and "Patrols by U-518," all published online at uboat.net.