The USS Robalo (SS-273) was a Gato-class World War II era submarine.
The namesake of the USS Robalo is any percoid fish of the family Centropomidae, occurring in warm and tropical (mostly marine) waters. Some of the larger species, such as the snooks, are important food fishes and many of the smaller ones are aquarium fishes.
The radio call sign of the USS Robalo was NAN-WILLIAM-KING-ABLE.
On June 22, 1944, the Robalo, captained by Lieutenant Commander Manning M. Kimmel, departed Fremantle to conduct her third and final war patrol. She had been ordered to patrol in the South China Sea in the vicinity of the Natuna Islands. 1
Manning M. Kimmel was the son of Admiral Husband E. Kimmel, who many people believe was unfairly made the scapegoat for the disaster at Pearl Harbor. The younger Kimmel graduated from the Naval Academy in June 1935. During the next three years Ensign Kimmel served on board the battleship Mississippi. In the latter half of 1938 he received submarine training at Groton, Connecticut and was assigned as a junior officer aboard the submarine USS S-38 (SS-143) from early 1939 until mid-1941. Lieutenant Kimmel then helped put the new submarine USS Drum into commission and served in her until November 1942, taking part in her first three war patrols. In January 1943 Manning Kimmel joined the pre-commissioning crew of USS Raton, then under construction. When she was commissioned in July 1943, he became her Executive Officer. After the Raton returned from patrol to Fremantle in January 1944, Kimmel joined Chester Nimitz, Jr. in the Prospective Commanding Officers pool. In March 1944, Rear Admiral Ralph Waldo Christie selected Lieutenant Commander Kimmel to be the new skipper of the USS Robalo. 2
Kimmel had sailed from Fremantle for his first patrol as captain of the Robalo on April 10, 1944. He stopped at Darwin to top off the Robalo's fuel and water on April 17th, and got underway again the same day. He steered the Robalo through the Balabac Strait on April 22nd, and headed for his assigned patrol area off the coast of Indochina. After completing his patrol assignments, he returned to Fremantle via the Karimata Strait and Java Sea, arriving there on May 30, 1944. In his patrol report, he claimed sinking a 7,500-ton enemy oil tanker. 3
Prior to getting underway on June 22, 1944 for the Robalo's third and final war patrol, Kimmel had been carefully briefed by the Operations Officer, his assistant, and the Intelligence Officer, and had met with Ralph Christie, the Commander of Task Force Seventy-One. Christie described his reasons for personally briefing commanding officers and his considerations for routing submarines to patrol areas via specific routes as follows:
It is my general custom to interview the commanding officer just before his departure in order to discuss the proposed patrol and to emphasize certain features of importance on methods and policies and in connection with the existing tactical situation. I always make a point of insuring that the commanding officer is satisfied with the material condition of his ship after the refit and that he is satisfied with the officer and enlisted personnel assigned to the ship and with the state of training. It has been my practice to emphasize the risk of enemy submarines from the minute of departure and during the return passage south of the Barrier because of the natural let down in vigilance with transiting these relatively peaceful waters. During this briefing, there is usually a free discussion of such things as the use of the SD radar, torpedo depth settings, the advisability of gun actions and such matters.
Submarines are routed to various patrol areas with the following considerations in mind: (a) shortest distance and time to area; (b) separation of submarines; (c) diversification of routes; (d) enemy opposition; (e) phases of the moon; (f) exploitation of traffic en route. We endeavor to insure that no one route becomes a "Beaten Path". If two or more depart at about the same time, we choose the routes to separate them in time and place to avoid the consequence of patrol vessels or planes being alerted by an attack, a sighting or a DF fix. Submarines are operated in groups only in open sea areas. 4
The Operation Order for the Robalo's final patrol directed her to top off her fuel at Operation Potshot in Exmouth Gulf, and then proceed via Lombok Strait, Makassar Strait, Sibutu Passage, Balabac Strait, and south of Dangerous Ground to her assigned patrol station in the South China Sea. Kimmel's orders contained specific information on how to transit the Balabac Strait and what to avoid, so as to steer clear of any known minefields. What Christie and Kimmel did not know was that the IJN minelayer Tsugaru had left Palau on March 24, 1944 with a mission to replenish the mines in the Balabac Strait. When the minelayer completed its work in the Balabac Strait, it headed south for Balikpapan, on Borneo's Makassar Strait coast.
24 March 1944:
Departs Palau. TSUGARU lays mines in the Balabac Strait, Philippines. 
2 April 1944:
Arrives at Balikpapan, Borneo.
 On 26 Jul '44, LtCdr Manning M. Kimmel's (son of Admiral H. E. Kimmel of Pearl Harbor) USS ROBALO (SS-273) is sunk W of Palawan Island in the Balabac Strait. ROBALO may have hit a mine laid by TSUGARU in Mar '44. On 13 Aug '44, LtCdr John D. Crowley's FLIER (SS-250) also hit a mine S of Palawan in the Balabac Strait that may have been laid by TSUGARU; however, some mines were also laid in the Balabac Strait in 1943. Crowley survived, but Kimmel was KIA. 5
Based on the above dates the new mines were likely seeded near the end of March 1944.
On July 2, 1944, Kimmel made a contact report stating Robalo had sighted a Fuso-class battleship with air cover and two destroyer escorts, just east of Borneo at 3°-29' N, 119°-26' E. However, he did not state whether or not he had attacked it. 6
The contact report was the last message ever received from the USS Robalo and when she did not return from patrol when expected, she was reported as presumed lost. The public announcement was made on September 6, 1944:
Navy Department Communiqué No. 540, September 6, 1944
1. The submarine USS Robalo is overdue from patrol and must be presumed to be lost.
2. The next of kin of personnel in the Robalo have been so notified.
It was not until the surviving crew members of the USS Flier (SS-250) were picked up at Palawan Island by the USS Redfin (SS-272), on the night of August 30-31, 1944, and brought back to Australia, that the story of what happened to the Robalo began to unfold fully. The early information came from what Commander James D. Crowley was told by Sergeant Pasqual de la Cruz, Philippines Army, U.S. Army Forces Far East (USAFFE). Cruz had been assigned to guide the Flier survivors to their rendezvous point with the USS Redfin. Crowley testified as follows regarding what he was told by de la Cruz:
Commander J. D. Crowley, U.S. Navy, took the stand voluntarily to testify concerning the loss of the U.S.S. Robalo, and was advised that the oath previously taken by him was still binding.
Examined by the investigating officer:
1. Q. Commander, do you have any information from the natives regarding what happened to the Robalo?
A. Yes, sir. Sergeant Pascqual de la Cruz, Philippine Army, U.S.A.F.F.E., whom I encountered at the guerrilla outpost at Cape Buliluyan, informed me on August 21st that he had recently returned from a reconnaissance trip to Balabac Island. This trip was made to verify a rumor that some Americans had been captured there. He received the following information which he told me. The U.S.S. Robalo was sunk by an explosion in the forward battery on 3 July 1944. The reported position of the vessel at the time of the explosion was forty miles west of Balabac Island. There were four survivors of Robalo who were found on the beach on Comiran Island. From his story, of which the facts are not clear, I arrived at three possible solutions as to the fate of the survivors: (1) that the four were surprised on the beach and jumped up, two escaped and two were captured; (2) in the foregoing event all four were captured; (3) in the foregoing event all four were captured and two were deliberately shot after capture. The names of the two survivors made prisoner were reported to me as Lieutenant Tucker and quartermaster Martin. One of the others apparently was the commanding officer of the Robalo, and no information exists or was given to me as to the identity of the fourth. The reason for the conflicting stories as to the fate of the survivors is that Sergeant de la Cruz received the information from different sources. One other thing that he also told me, that the Robalo departed Port Darwin on a date in late June which I do not remember accurately. I believe it was the 29th. Apparently it came from the survivors. The two prisoners are reported to have been sent to the Japanese prison camp at Puerto Princesa, Palawan. This is all the information that I have. 7
Ralph Christie and his staff probably realized right away there was a problem with this information because it conflicted with the instructions they had placed in the Robalo's Operation Order. Specifically, the Operation Order instructed Kimmel as follows:
(2) When directed, about June 22, 1944, depart FREMANTLE for EXMOUTH GULF via the Bombing Restriction Lane; there refuel to capacity.
(3) Thence proceed via LOMBOK STRAIT, MAKASSAR STRAIT, SIBUTU PASSAGE, BALABAC STRAIT, and South of DANGEROUS GROUND to patrol the SOUTH CHINA SEA and approaches to the GULF of SIAM South of latitude 9° North and West of longitude 112° East, paying particular attention to SINGAPORE - SAIGON, SINGAPORE - MANILA, and SINGAPORE - EMPIRE traffic routes. 8
The Robalo had returned to Fremantle after her second patrol. It made sense that she should also leave from there for her third patrol. She would not stop at Port Darwin to top off her fuel as she had done on her second patrol. The route she would follow to the South China Sea had been carefully planned - Fremantle to Exmouth Gulf and then through the Barrier at Lombok Strait.
Sometime after the Flier's crew returned to Australia and probably after the Flier and Robalo investigations, as well, new intelligence about the Robalo was received. It was based on information in a note found by an American Army prisoner on August 2, 1944, at Puerto Princesa Prison Camp on Palawan Island in the Philippines, and other information provided by the surviving wife of a dead Filipino guerrilla leader. From these sources it was concluded that the Robalo was probably sunk on July 26, 1944, two miles off the west coast of Palawan Island in Balabac Strait from an explosion in the vicinity of her after battery, likely caused by an enemy mine. Her skipper, Manning Kimmel, and perhaps six men may have survived the explosion. Four of them swam ashore, and made their way up the east coast of Palawan Island to look for friendly guerrilla fighters. They were captured by Japanese military police and jailed at the Puerto Princesa Prison Camp. It is very likely that all of them were either killed by the Japanese or died in captivity. 9
It is important to emphasize the note described above specifically cited the loss of the Robalo on July 26, 1944 by contact with a mine, her hull number (i.e., SS-273), and named the four survivors held in the prison. The Army prisoner gave the note to a U. S. Navy POW, who later made contact with Trinidad Mendoza, the widow of the Filipino guerrilla leader Captain Higinio A. Mendoza, Sr., M.D., who was a Captain in the Philippines Army Medical Reserve and governor of Palawan from 1933 to 1938. In February 1942, he organized the first Palawan-based guerrilla unit, A Company. As the Japanese prepared to occupy Puerto Princesa in May 1942, Captain Mendoza supervised the town's evacuation. He moved his headquarters to Tinitian, north of Puerto Princesa. Captain Mendoza assisted some American POWs who escaped from the Puerto Princesa prison camp. Captain Mendoza’s guerrilla unit also captured and executed many Japanese spies in Puerto Princesa. As a result, the Japanese made his capture a high priority. On January 7, 1944, they arrested him near Tinitian. On January 24, 1944, he was taken to a location in Canigaran, where he was forced to dig his own grave. He was then shot and beheaded. The information the U. S. Navy POW gave to his widow was eventually relayed to Ralph Christie. 10
In his book Sink 'Em All, Vice Admiral Charles A. Lockwood described this intelligence and its eventual refinement:
On August 2, 1944, a note dropped form the window of a prison cell in which the survivors from Robalo were held, was picked up by an American soldier in a work detail and given to H. D. Hough, Y2/c, another prisoner. Two days later Hough contacted Mrs. Trinidad Mendoza, wife of guerrilla leader, Dr. Mendoza, who furnished further information on the survivors. From these sources, we put together the following facts.
Robalo was sunk July 26, 1944, two miles off the western coast of Palawan Island as a result of an explosion of her after battery. Four men swam ashore, an officer, and three enlisted men: Samuel L. Tucker, Ensign; Floyd G. Laughlin, QM1/c; Wallace K. Martin, SM3/c; and Mason C. Poston, EM2/c. They made their way through the jungles to a small barrio northwest of the Puerto Princesa Camp. They were captured there by Japanese military police and confined in the jail. They were held for guerrilla activities rather than as prisoners of war, it is said. On August 15, they were taken off by a Jap destroyer, and no other information is known regarding their destination or whereabouts. It is possible that they were executed by the Japanese or that the destroyer in which they were embarked was sunk. At any rate, they were never recovered, and their note stated that there were no other survivors.
It is doubtful that a battery explosion could be sufficiently violent to cause the sinking of the ship and it is expected that the loss of the Robalo was caused by an enemy mine. 11
Intercepted Japanese radio messages indicated that the four Robalo survivors were placed aboard the merchant vessel Takao Maru on August 19, 1944, and then on the light cruiser Kinu on August 22, 1944. Kinu brought them to Manila on August 25, 1944. The evidence trail ends at Manila. Nothing more is known of what became of the Robalo survivors after they landed there. 12
The Robalo could have hit one of the new mines planted by Tsugaru or perhaps one of the older ones which had become a floater. We may never know for sure. However, we do know that the Robalo and the USS Flier were eventually avenged by the USS Darter (SS-227).
29 June 1944:
[TSUGARU] Departs Halmahera for Manila. In the early afternoon, off Morotai Island, near Biak, Cdr (later Captain) David H. McClintock’s DARTER (SS-227) sights a large minelayer under escort by two 300-ton subchasers and an aircraft. Using an out-dated reference, McClintock misidentifies TSUGARU as the similarly configured, but somewhat older, minelayer OKINOSHIMA. At 1356, DARTER's crew readies all torpedo tubes. As TSUGARU approaches from starboard, Cdr McClintock observes a floatplane on her deck. 
At 1425, McClintock fires a full bow spread of six torpedoes with a run of about 2,350 yards. Two torpedoes hit and TSUGARU goes dead in the water. At 1432, the subchasers begin dropping a total of 24 depth charges, but DARTER goes deep and escapes undamaged.
At 1449, TSUGARU sinks at 02-19N, 127-57E. Captain Nakatsu is KIA. He is promoted Rear Admiral, posthumously.
10 August 1944:
Removed from the Navy List.
 Probably a two-seat Kawanishi E7K "Alf" float biplane. 13
Manning Kimmel's brother, Thomas, was also a Fremantle-based submarine commander during the Pacific War. After the war, he wrote a letter to Clay Blair, Jr. raising doubts about Ralph Christie's wisdom in forcing Fremantle boats to transit the heavily mined Balabac Strait late in the war. He wrote: "The Japanese were obviously in retreat and the urgency for transiting a dangerous strait with known minefields was certainly greatly reduced if not non-existent." Vice Admiral Thomas C. Kinkaid relieved Christie of command of submarine operations at Fremantle effective December 30, 1944, and replaced him with Rear Admiral James Fife. No specific reason for the change in command was cited, however the Robalo's skipper, Manning Kimmel, was Kinkaid's nephew. 14
The Robalo earned two battle stars for her World War II service. The JANAC postwar assessment and the more recent Alden-McDonald analysis did not validate any of the enemy vessel claims in the Robalo's war patrol reports. Her SORG score is one vessel sunk for 7,500 tons and one vessel damaged for 6,200 tons. 15
A list of the personnel lost with Robalo is maintained at On Eternal Patrol.
Also see: Belated Recognition For Robalo.
I have inserted below the Finding of Facts and the Opinion from the "Record of Proceedings of an investigation conducted at the headquarters of the Commander Submarines Seventh Fleet by order of the Commander in Chief, United States Fleet and the Chief of Naval Operations to investigate the circumstances connected with the loss of the U.S.S. Robalo and the loss of the U.S.S. Flier, 14 September 1944." I have only included the items which pertain to the USS Robalo, unless it was impossible to separate them from information relating to the USS Flier, in which case both are presented. In two instances I had to insert findings of fact out of numerical order when a Flier fact was also deemed applicable to the Robalo by the investigator. 16
FINDING OF FACTS
25. That, according to all available intelligence information, the Japanese use only contact mines. Minefields laid in areas subject to rough seas or currents will not normally endure for periods longer than six months. Japanese mines have been found adrift in the vicinity of the Sulu Archipelago.
26. That the U.S.S. Robalo, in accordance with Task Force Seventy-One Operation Order Number 80-44, "Exhibit 2", departed Fremantle 22 June 1944 to patrol in the South China Sea and approaches to the Gulf of Siam south of latitude 9° North and west of longitude 112° East. This was changed on 16 July 1944 to the area west of longitude 108° East until Ray's departure from the area. Robalo was directed to fuel at Exmouth Gulf, thence proceed via Lombok Strait, Makassar Strait, Sibutu Passage, Balabac Strait, and South of Dangerous Ground.
27. That, prior to departure, the Operation Order and the annexes were explained to the commanding officer by the Operations Officer, his assistant, and the Intelligence Officer, and that he was thoroughly briefed by these officers, and finally by Commander Task Force Seventy-One, and was given all available information concerning the enemy minefields.
28. That, prior to departure from Fremantle, Robalo had had a normal refit, had been ranged to determine her degaussing condition, and materially was ready for patrol in all respects.
29. That the Robalo, after her refit, had been given the customary training in approaches and fire control under the supervision of Commander Willis A. Lent, U.S. Navy. Her crew consisted of eight officers and seventy-three enlisted men, a total of eighty-one. The commanding officer, Lieutenant Commander Manning M. Kimmel, was an experienced submarine commanding officer, having made five patrols. The officers and the enlisted personnel were well trained and qualified in all respects to take a submarine on war patrol.
30. That Robalo's Operation Order, in paragraph (x) (4) stated, "Stay clear of readily mineable waters in the vicinity of the Sulu Archipelago and Balabac Strait. Use deepest water routes in transiting Sibutu Passage or Balabac Strait", and that in the intelligence annex, the route followed by the Crevalle through the Balabac Strait - Nasubata Channel - was given.
31. That Fact Number 11 applies to the transiting of Nasubata Channel in the case of the Robalo. [Fact Number 11 is inserted below.]
11. That forty transits of Balabac Strait have been made and those of recent dates are as follows:
|10 February 1944||Crevalle|
|13 February 1944||Tinosa|
|17 February 1944||Puffer|
|18 February 1944||Ray|
|24 February 1944||Bluefish|
|25 February 1944||Bonefish|
|26 March 1944||Bluefish|
|19 April 1944||Crevalle|
|22 April 1944||Robalo|
|8 May 1944||Crevalle|
|10 July 1944||Lapon|
32. That on 2 July 1944 Robalo reported her 0800 hour position as 3°-29' North and 119°-26' East, and that she had sighted one enemy battleship and two destroyer escorts which had gotten by her.
33. That this position reported by Robalo is her last known position.
34. That from this position at 0800 hour, 2 July, she could have transited Balabac Strait - Nasubata Channel - the night of 3-4 July 1944.
35. That on 11 August 1944, and thereafter, unsuccessful attempts were made to communicate with the Robalo.
36. That it cannot be stated how the Robalo was lost. After reporting the enemy battleship and two destroyer escorts on 2 July, she may have been DF'd and sunk by enemy surface forces or planes. There are well formed rumors that survivors from the Robalo were taken by the enemy on Balabac Island. The Robalo could have transited Balabac Strait - Nasubata Channel - on the night of 3-4 July, and could have been sunk by a mine while transiting this channel.
37. That, referring to paragraph 22 of the Finding of Facts [paragraph 22 is inserted below], Sergeant Pascqual de la Cruz gave the following information which, while not factual, is the best obtainable:
(a) Robalo sank on 3 July 1944 as a result of an explosion in the forward battery compartment.
(b) The reported position of the Robalo was forty miles west of Balabac Island.
(c) There were four survivors of the Robalo who were found by the Japanese on Comiran Island and taken prisoner.
(d) Of the four prisoners, one was the commanding officer, one was Ensign Samuel L. Tucker, U.S. Naval reserve, and one was Martin, Wallace K., signalman third class, and the identity of the fourth was not known.
(e) The commanding officer and the unidentified prisoner were shot, either deliberately or while trying to escape.
(f) Ensign S. L. Tucker and "quartermaster" Martin survived and are war prisoners at Puerto Princesa, Palawan.
(g) Sergeant de la Cruz also told Commander Crowley that the Robalo had departed Port Darwin on a date in late June, a fact which he had no means of knowing, unless he had learned this from the Japanese or from the survivors of the Robalo. This gives credence to his story, as does also the fact that he had the names of two of the crew, namely, Ensign Tucker and "quartermaster" Martin.
22. That at Cape Buliluyan on Palawan Island Commander Crowley encountered Sergeant Pascqual de la Cruz, Philippine Army, U.S.A.F.F.E., who had just returned from a reconnaissance trip to Balabac Island and he gave Commander Crowley information concerning the Robalo.
1. That the Operation Orders for the U.S.S. Flier and for the U.S.S. Robalo, prepared by Commander Task Force Seventy-One, contained complete directives and information for the routing of the submarines to their respective patrol areas.
2. That from all available intelligence information the routing of these submarines through Balabac Strait - Nasubata Channel - was the safest route.
3. That in the loss of the U.S.S. Flier and the U.S.S. Robalo, no blame was incurred by the interested party, Rear Admiral R. W. Christie, U.S. Navy, Commander Task Force Seventy-One, or any member of his staff.
4. That in the loss of the U.S.S. Flier, no blame was incurred by the defendant, Commander J. D. Crowley, U.S. Navy, the commanding officer, or any member of the Flier's crew.
5. That in the loss of the U.S.S. Robalo, there is no evidence of any blame that can be ascribed to the commanding officer, Lieutenant Commander Manning M. Kimmel, U.S. Navy, or to any member of the crew of the U.S.S. Robalo.
6. That in the loss of the U.S.S. Flier, while transiting the Nasubata Channel, must be ascribed to the hazards of war.
7. That in the loss of the U.S.S. Robalo, in a position unknown, must be ascribed to the hazards of war.
1. Submarine war patrol reports on CD, USS Robalo (SS-273), "A Brief History of USS Robalo (SS-273)," p. 2-3.
2. Blair, Clay Jr., Silent Victory: The U. S. Submarine War Against Japan, p. 497.
3. Submarine war patrol reports on CD, USS Robalo (SS-273), Report of War Patrol Number Two.
4. Submarine war patrol reports on CD, USS Robalo (SS-273), "Record of Proceedings of an investigation conducted at the headquarters of the Commander Submarines Seventh Fleet by order of the Commander in Chief, United States Fleet and the Chief of Naval Operations to investigate the circumstances connected with the loss of the U.S.S. Robalo and the loss of the U.S.S. Flier, 14 September 1944," p. 5-6. Hereafter referred to as The Robalo Investigation.
5. Hackett, Bob, Sander Kingsepp and Peter Cundall, "IJN Minelayer TSUGARU: Tabular Record of Movement," published online at Combined Fleet.
6. United States Submarine Losses World War II, p. 100.
7. The Robalo Investigation, p. 8-9. I note that de la Cruz's first name is consistently misspelled in the investigation report.
8. The Robalo Investigation, Exhibit 3.
9. Blair, Clay Jr., Silent Victory: The U. S. Submarine War Against Japan, p. 687.
10. Ibid.; Sturma, Michael, The USS Flier: Death and Survival on a World War II Submarine, p. 82; Willoughby, Charles A., The Guerrilla Movement in the Philippines: 1941-1945, p. 506-508 and 572; "The Mysterious Doctor Mendoza," published online at Pips & Blips.
11. Lockwood, Charles A., Sink 'Em All: Submarine Warfare in the Pacific, p. 197-198.
12. Michno, Gregory F., Death on the Hellships: Prisoners at Sea in the Pacific War, p. 272-273; Hackett, Bob and Sander Kingsepp, "IJN KINU: Tabular Record of Movement," published online at Combined Fleet.
13. Hackett, Bob, Sander Kingsepp and Peter Cundall, "IJN Minelayer TSUGARU: Tabular Record of Movement," op. cit..
14. Blair, Clay Jr., Silent Victory: The U. S. Submarine War Against Japan, p. 688 and 814-815.
15. Alden, John D., and Craig R. McDonald, United States and Allied Submarine Successes in the Pacific and Far East During World War II, Fourth Edition, see USS Robalo (SS-273), Attack Nos. 1624 and 1966; Submarine war patrol reports on CD, data collected by the Submarine Operations Research Group (SORG) in the report "Results of U. S. Submarine War Patrols Listed Alphabetically by Name of Submarine," see USS Robalo (SS-273).
16. The Robalo Investigation.