Dorado Loss Scenario

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Introduction

Until the wreck site of Dorado is found, no one, including the members of this team, can say definitively what actually happened to Dorado and her crew. The case that we will present below is based on meticulous research in official Navy documents, especially excerpts from the two official inquiries into her loss. It is as fact based as we can possibly make it at this time. In order to round out the narrative, there are times in which Thaddeus and the team have used informed speculation based on years of research and personal experience. Every effort has been made to keep speculation to a minimum. There are times in which the narrative gets rather vague, and that is because no verifiable information about those periods exist. The team used first hand personal experience in submarine operations to help fill in the gaps. An example would be the period of Dorado's transit south through the Atlantic.

What we present below is the scenario as we believe it to be at this time, and it admittedly is not the only possibility. Subsequent research and/or actually finding the wreck site has the potential to radically alter the story. Thank you for your interest. If you have questions or comments, please direct them to ussdoradoproject@gmail.com.

The Departure

USS Flasher (SS-249), Dorado's sister boat, on sea trials in 1943. Dorado would have been configured very close to this when she left for war. NARA photo #80-G-450241 via Navsource.net.
On the morning of October 6, 1943, Dorado backed smartly out of her slip at Submarine Base New London, Groton, CT., put on some left rudder, and swung her stern to the north and up river. Expertly timing the swing, LCDR Schneider, present on the bridge with several other crewmen, ordered zero rudder and all stop. He then ordered "all ahead two thirds" and Dorado began her trip down the Thames River, headed to Long Island Sound and eventually the Atlantic Ocean.

She passed under the U.S. Route 1 bridge, with the venerable structure lifted open to allow the boat to pass underneath. She passed the main Electric Boat facility on her port beam, and a little further downstream she passed the Victory Yard where she was built. Men and women toiling in the cool October air on Dorado's sister subs paused for a moment, proudly acknowledging their handiwork as the submarine passed. They wished her luck as she headed off to war.

The crew was experiencing a mixed set of emotions. They had come to enjoy their stay in Connecticut and had a deep appreciation for the hard work put forth on their behalf by the Electric Boat personnel. Friendships had developed with the workers that the men valued. Some of the crew had brought family members to the Groton/New London area and they were now leaving that all behind; a touch of sadness prevailed as they sailed down the Thames River. There was also a palpable sense of anxiety as they pushed the bow of the boat into the unknown. The experienced men knew of the combat that laid ahead, the inexperienced men put on a brave face as they tamped down their fears. All of that was tempered by the excitement of finally moving forward. They were well trained and confident in themselves and their shipmates, and despite lingering anxiety they eagerly anticipated the adventure that laid ahead.

Fishing vessels hailed her as she passed the mouth of the Thames and Schneider rang up an ahead standard bell with turns for 14 knots. The bridge watch team kept a wary eye on the Fisher's Island and Montauk ferries as they passed, with a little maneuvering left and right intended to keep the ferries at a safe distance. Clearing Fisher's Island she made a slight turn to the southeast, putting her on course to pass down the middle between Montauk Point on her starboard side and Block Island on her port. Down below in the conning tower and control room the Quartermasters and the Navigator were busy piloting the submarine, shooting bearings with the periscope to land-based navigation aids, using those bearings to triangulate their position on the chart. With Montauk Point on their starboard quarter, they took their "point of departure", i.e. the last confirmed land-based navigational fix, and headed out into the blue Atlantic.

The Voyage

Graphic ©Thaddeus Weaver, 2025
Dorado's voyage orders were referred to by the Navy as a Movement Order, or MOVORD. Dorado's MOVORD for the initial leg contained seven waypoints, Able to George. They would route her out into the Atlantic and south towards the Caribbean. Her destination was Submarine Base Coco Solo, on the Atlantic side of the Panama Canal near the city of Colon. She would briefly stop there to refuel and reprovision prior to her transit through the Panama Canal and the second leg out across the Pacific to Hawaii.

The final waypoint was Point George, 15 nautical miles (NM) north of the Cristobal Breakwater, a structure that defined the harbor for Cristobal and Colon. At George the Dorado was to rendezvous with a U.S. destroyer, who would escort Dorado on the surface the last few miles to the submarine base. This rendezvous was supposed to happen at 1100 local (11:00 am) on the afternoon of October 14. This date/time is very important for several reasons:

  • Being escorted into the harbor by the destroyer would prevent Dorado from being mistaken for a German submarine (known to be operating in the Caribbean) and being fired upon by friendly forces. Being early or late for the rendezvous was frowned upon, as it would cause serious tactical, operational, and logistical problems that the Navy wanted to avoid.

  • Traffic through the canal was very high, and specific times were assigned to ships for passage so that the possibility of traffic jams was avoided. If Dorado missed her transit time, it would delay her voyage all the way to Pearl Harbor and the war zone and exacerbate the operational and logistical issues previously mentioned.

  • The date/time of her arrival at Point George also dictated the speed of her transit, known properly as her "speed of advance" (SOA). To make Point George on time her SOA was 14 knots. This was also a fuel efficient speed and was well within her maximum surface speed of 21 knots. However, it also dictated that Dorado make the transit mostly on the surface, as her maximum submerged speed was only eight knots. LCDR Schneider had the discretion to submerge as he saw fit for drills and training, but he had to maintain the average speed of 14 knots in order to make George on time.

Dorado would also make the voyage under a condition known as "radio silence". This was a procedure in which Dorado was not to use her radio for routine transmissions, out of a concern that German submarines in the area might use those transmissions to triangulate her position. The crew could receive broadcasts, and Schneider had the latitude to report serious circumstances if he felt it was warranted, but things like routinely reporting her position and administrative message traffic was not allowed.


Example of a zig-zag course, intended to disrupt the aim of an attacking submarine.
Another element of Dorado's voyage was that she was following a "zig-zag" course. This was a tactic that was intended to make it difficult for an enemy submarine to properly aim its torpedoes. German submarines were known to be operating in both the Atlantic and Caribbean and the danger of being attacked by one of them as Dorado made her transit south was very real. The defensive tactic of constantly shifting your course to either side of the base course would hopefully foul an enemy submarine's fire control solution, leading to misses. It resulted in it taking longer for Dorado to make her voyage, but this was all figured into her MOVORD timing.


Graphic ©Thaddeus Weaver, 2025
The final element of Dorado's voyage south to Panama was the imposition of a Submarine Sanctuary Zone around the submarine. As the graphic shows, this was a moving zone centered on the submarine's "point of intended movement" or PIM. The PIM at any given time was dictated by the the position that Dorado should be at given her SOA. Dorado's track, her SOA, and the dimensions of this moving sanctuary zone were transmitted to all Allied commands in the Atlantic and Caribbean. The purpose of which was to prevent a blue-on-blue, or friendly fire incident from happening. Under no circumstances were any attacks to be made on suspected submarines within this zone, unless the ID of the submarine could be absolutely confirmed.

The zone was big enough to allow the zig-zag course to be conducted, and for periodic dives for training and drills. However, it was incumbent upon the crew of Dorado to ensure they stayed within the zone at all times. Allied surface and aerial forces were understandably a bit on edge due to the threat of German submarines, and this zone was intended to eliminate the "friendly" threat to U.S. submarines transiting to Panama.

Prelude: October 11 and 12, 1943

The trip south through the Atlantic had not been a leisurely pleasure cruise. Schneider used the opportunity to constantly drill the crew and hone their skills. Drills of all sorts were run, ranging from fire and flooding to mock torpedo attacks. He would "crash dive" the boat at random intervals, a stop watch in his hand to evaluate how long it took to get the boat from fully surfaced to periscope depth (65 feet). A well trained crew could dive the big fleet boat in 35-40 seconds.

Around mid-day on October 11, the boat was approaching Point Dog, and they raised Cape Engano on the eastern tip of the island of Hispaniola right on time. They proceeded apace through the Mona Passage between the Dominican Republic and Puerto Rico, passing through Point Easy and out into the Caribbean. Dorado's base course between Points Easy and Fox was 243° true, or southwesterly, with the zig-zag plan having Dorado jinking left and right of that course.

Graphic ©Thaddeus Weaver, 2025
By the late afternoon on October 12, Dorado had company on her transit across the Caribbean Sea. Allied convoy GAT 92 was enroute from Guantanamo Bay, Cuba to Trinidad with nine ships and was in the central Caribbean north of Dorado's position. The convoy originally consisted of 32 ships when it first departed New York, but some ships stayed in Guantanmo. Escorted by two Dutch and three U.S. patrol craft, the convoy was on a southeasterly course of 143° true. They were set to cross Dorado's path some time that evening. The convoy commander had been fully briefed on Dorado's transit, and likewise Schneider and his crew knew of the convoy and their intentions. In addition to the five surface craft, the convoy fell under the protective umbrella of U.S. Navy patrol squadron VP-210 based at Guantanamo. The squadron consisted of 12 Martin PBM-3S Mariner flying boat patrol aircraft. On the evening of October 12th, one of these Mariners was flying cover over the convoy. This aircraft carried the call sign 210-P-9.


Graphic ©Thaddeus Weaver, 2025
Unbeknownst to the convoy commander or the crew of Dorado, the crew of 210-P-9 had been incorrectly briefed on Dorado's actual position, based on an incorrect plotting of Dorado's course on the surface ship plotting board at the Joint Operations Center, Naval Operating Base, Guantanamo, Cuba. Because of this LT(jg) Daniel T. Felix, Jr., the aircraft commander and left seat pilot, and his crew believed that Dorado's base course was 31 NM miles to the south of where she actually was. 210-P-9 took off at dutifully at 1540 (3:40 pm) and by that evening was patrolling out ahead of the convoy. They made radar contact on a surface target at 2039 on October 12, and Felix and the crew made the justifiable assumption that it was an enemy U-boat because it was in an area where no U.S. submarine was supposed to be, or so they believed.










The critical 13 minutes: 2039-2052, October 12, 1943

Author's note: in this section, any text in italics will be speculation based on first hand knowledge of submarine operations and established WWII USN submarine tactical procedures. Our intention is to provide some context as to what we believe was happening onboard Dorado during these critical 13 minutes. We understand if you view those passages through a vaguely unconvinced lens. The remainder of the text, however, is fact based, taken from official U.S. Navy sources.

Upon detection of the surface target on radar, Felix continued to fly the PBM on its southerly course of 190° true. His intention was to visually acquire the target in order to make an evaluation. Sure enough, at eight nautical miles out the faint silhouette of a small ship was seen with binoculars in the bright moonlight. Felix immediately made a turn to the right. The intention was to swing around and place the target "up moon", that is silhouetted with the moon in the background. That would give his crew the maximum visibility of the target while at the same time hiding their approach in the black background.

Graphic ©Thaddeus Weaver, 2025

Schneider was lying in his bunk in his small stateroom in the forward battery compartment and was casually leafing through a novel when the phone next to him buzzed. It was the Officer of the Deck on the bridge. "Captain, OOD. The previously detected aircraft now has a decreasing range, 10 miles and closing steadily." Schneider replied, "Very well. I'm on my way up." Schneider quickly put on his shoes and headed aft to the control room. He clambered up the ladder to the conning tower and went to the radar station on the starboard side. There he peered over the shoulder of the Radioman who was manning the station. The small circular A-scope screen of the SD air search radar showed the blip and its decreasing range. The SD set was a range only radar and did not provide a bearing. However it could safely be surmised that it was north of their position as that is the direction of the convoy. He wasn't overly concerned at this point, as he knew that it was an American aircraft protecting the convoy (the Germans obviously were not operating aircraft in the Caribbean), and he knew that Dorado was well within the sanctuary zone where no attacks were allowed.

He moved to his left and glanced at the gyrocompass repeater in front of the helmsman and saw that they were steady on course 310° true. The OOD was dutifully following the zig-zag plan and they were now to the right of their base course of 243° and temporarily headed northwest. He turned to the right and grabbed the rungs of the ladder to the bridge. Squeezing up through the open hatch, he was greeted by the Officer of the Deck announcing, "Captain on the bridge."

Lieutenant Felix came out of the wide sweeping left turn and steadied up on course 090°, or due east and steadied at an altitude of 1000 feet. At 2049 at a range of three nautical miles, both pilots and another crewman stationed at the nose gun station were able to confirm that the target was indeed a submarine. Felix faced a dilemma, should he attack or try to confirm identity? Quickly mulling it over he realized that everything he had been briefed on, everything that he had trained for, and all of the information that the had told him that this was a German U-boat. He made the decision to attack. He begins a slow descent to release altitude at a speed of 170 knots.

Fortunately, Schneider's eyes were already adapted to the dark. He had been wearing red lens goggles while resting in his cabin, and red lights were on in all compartments, preventing night blindness. About six minutes had elapsed since he had arrived on the bridge, and he was diligently scanning the skies with binoculars, along with the two lookouts, the Officer of the Deck, and one Quartermaster. Suddenly, the port lookout calls out, "Aircraft contact, two points on the port bow." Schneider swings around to the left, raises his binoculars, and peers intently into the blackness. A few seconds later he catches a faint moving shadow, close to the horizon, and the dim flashes of engine exhaust from two engines. He immediately thought "Looks like a PBM". Despite knowing this was a friendly aircraft, he was immediately wary. "Don't like the look of this", he thought.

Graphic ©Thaddeus Weaver, 2025
Graphic ©Thaddeus Weaver, 2025
Felix made a nearly perfect attack run. At 2051 he released three Mk 47 depth charges and one Mk 4 Mod 4 100 lb general purpose bomb from the two bomb bays in the engine nacelles behind each engine. As you can see from the Court of Inquiry graphic on the left, the bomb and the third depth charge most likely did not detonate, as the plane was too low for the bomb to arm, and there were problems found with the arming mechanism for the third depth charge when the plane returned to base. It should be emphasized that this pattern is an estimate only. NONE of the crew actually witnessed the impact of the weapons and they were too far away to have heard any explosions. It is likely that there was a little left\right separation of the ordnance, as two of them dropped from the left bomb bay and two from the right. However, if this graphic is at least close to reality, then the impact of the dud bomb and the detonation of the two other depth charges had the potential to cause serious damage to Dorado.

Time had slowed for Schneider, and he stared at the approaching shape for what seemed like minutes, but was actually just three seconds. "Nope," he thought, "Don't like this at all." He pushed past the OOD and reached for the diving alarm switch. Turning slightly to his left he bellowed "Clear the Bridge" and pulled the diving alarm switch twice. The "aaoogahs" of the diving alarm jolted everyone awake below and initiated the maneuver that they had practiced interminably. Schneider's call of "Dive, dive" over the 1MC PA circuit backed up the urgency and instantly main ballast tanks vents were opened, engines were shut down, intake and exhaust valves shut, and the bow planes were rigged out. Schneider counted men as they jumped down the hatch, waiting until he was satisfied that all on the bridge were below. As he half fell, half climbed down the ladder himself he grabbed the hatch lanyard and pulled the hatch shut behind him, with the Quartermaster reaching up and dogging the hatch down tight. He yelled down the hatch to the control room, "Diving Officer, make your depth 200 feet smartly". He then ordered, "Helm all ahead flank". Back aft in the maneuvering room the electricians on watch positioned large switch levers to line up the two batteries in series, greatly increasing their voltage output, and they cranked the speed rheostats for the motors against their stops. Schneider felt the satisfying downward tilt of the deck and quietly muttered, "This is going to be close..."

No sooner had the words come out of his mouth when a loud WHANG preceded a jump in the deck, and the whole boat rattled. The 100 lb bomb had struck the aft part of the conning tower fairwater and although it did not detonate, it had enough kinetic energy to wreck the man-sized main air induction and main ventilation valves enclosed there. One second later the boat was pummeled by the nearly simultaneous detonations of two of the depth charges. Men were thrown to the deck, the lights went out, and the crew struggled to regain control as they nosed downward.

Graphic ©Thaddeus Weaver, 2025
As soon as the ordnance was away, Felix threw 210-P-9 into a hard left turn. His intent was to circle back and conduct a re-attack if necessary. One minute later, at 2052, they arrived over the attack datum point and dropped a yellow flare. All that was revealed in the flickering light of the flare and the glare of the moon was a large patch of white, disturbed water and bubbles. No wreckage and no oil slick was observed. Admittedly, this is the exact scene that would have been observed if the boat had merely dived under its own power, but without any confirmatory evidence Felix and his crew were confident that they had at dealt the "U-boat" a heavy blow, and they continued on patrol, wary and on guard.

What happened to the Dorado at this point is very difficult to ascertain. Any number of circumstances could have befallen the boat, but the lack of wreckage and an oil slick on the surface means that at least she departed the surface intact. Predicated on the FACT that Dorado never made her rendezvous at Point George on the afternoon of October 14, some of the post-bombing scenarios may include:

  • Dorado was not damaged at all. Schneider makes a hard left turn to clear the attack datum point while simultaneously speeding up and getting the boat down to a safe depth. She then sinks later due to an unrelated equipment casualty.
  • Dorado suffered some equipment derangement, possibly including a loss of electrical power, possibly including a "jam-dive" on the stern diving planes, etc. The crew loses control of the boat and she sinks below crush depth.
  • A combination of the two above. Dorado suffered some damage, i.e. flooded engine induction piping, jam-dive on the stern planes, etc., but was able to fight the damage and keep the boat going for perhaps up to a half-hour or more, before succumbing to the circumstances and sinking.

Ultimately, it will require that the wreck be found and surveyed before many of these questions can be answered.

Background: Facts, assumptions, and conclusions


More to come, work in progress.



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Thaddeus Weaver & David Johnston
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