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 understand it 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 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 1300 local (1:00 pm) 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.
• Traffic through the canal was 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.
  
  
• 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 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.

October 11 to 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 the Mona Passage between the Dominican Republic and Puerto Rico, passing through Point Easy and out into the Caribbean.

Graphic ©Thaddeus Weaver, 2025

By October 12, Dorado had company on her transit across the Caribbean Sea.

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Thaddeus Weaver & David Johnston
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