The cruiser "9 de Julio" bombs positions in Mar del Plata.
The Sea Fleet on the Attack
Mar del Plata. Fuel depots in flames. (Photo: Isidoro Ruiz Moreno, La Revolución del 55, Tomo II)
Until the night of the 18th, no one knew where the Sea Fleet was located. At the time of the outbreak, the fleet was anchored in Puerto Madryn and consisted of the cruisers 17 de Octubre and La Argentina; the destroyers Buenos Aires, San Luis, Entre Ríos, and San Juan; the frigates Hércules, Heroína, and Sarandí; the salvage ship Charrúa; and the repair ship Ingeniero Iribas, under the command of Captains Fermín Eleta and Adolfo Videla, Commanders Eladio Vázquez, Benigno Varela, Aldo Abelardo Pantín, Mario Pensotti, Pedro Arhancet, Leartes Santucci, and César Goria, Commander Marco Bence, and Commander Jorge Mezzadra respectively.
Vice Admiral Juan C. Basso commanded the fleet from his flagship, the 17 de Octubre, assisted by Rear Admiral Néstor Gabrielli, commander of the Cruiser Force, aboard La Argentina; Captain Raimundo Palau, commander of the Destroyer Squadron, aboard Entre Ríos; and Captain Agustín Lariño, commander of the Frigate Division, aboard Hércules. On the 17 de Octubre were also the Chief of Operations, Commander Enrique Gunwaldt, and Captain Raúl Elsegood, Chief of Staff.
The first sign of the uprising reached the fleet at 08:22 on September 16, when Vice Admiral Basso received a communication from the Naval Operations Command informing him of recent events. Two and a half hours later (11:00), rebel officers led by Captain Agustín P. Lariño and Commander Aldo Pantín gathered aboard the Hércules to begin the mutiny and take control of the fleet.
As planned, Grunwaldt, supported by Captain Manuel Rodríguez, the Communications Chief Captain Félix E. Fitte, and Lieutenant Rodolfo Fasce, moved to the 17 de Octubre with the mission to subdue its commander and Captains Raúl Elsewood and Fermín Eleta. At gunpoint, they were locked in a cabin under the guard of Lieutenant Ricardo Bustamante. Ruiz Moreno recounts that during this time, Lieutenant José A. Lagomarsino proceeded to rip out the internal telephone cables, thereby cutting off communication for the loyal elements on board.
Minutes later, Commander Carlos A. Borzone reported from La Argentina that the situation on the ship was under control, as it was on the Buenos Aires, Entre Ríos, and the rest of the units. On the Buenos Aires, Rear Admiral Gabrielli was subdued by Captain Videla; on the Entre Ríos, its commander, Captain Vázquez, detained his second-in-command and a lieutenant; and on the last vessel, Captain Pantín did the same with Captain Palau, the head of the Destroyer Squadron.
A confusing incident occurred on the flagship when Captain Lariño, arriving from the Hércules, appeared. Suspecting his intentions, Captain Grunwaldt ordered his arrest, unaware that Lariño was a declared supporter of the revolution. He had Lariño locked in the commander's cabin. Captain Alberto Tarelli had to intervene to clarify the situation, securing Lariño’s immediate release. As Ruiz Moreno explains, Lariño remained on board the 17 de Octubre as a tactical command officer and never returned to the Hércules.
Before departing, Lariño ordered that the detained officers be transferred to the Ingeniero Iribas, which at that time was docked in Puerto Madryn. Deeply saddened by the situation of his superior, Vice Admiral Basso, whom he respected and admired, Lariño instructed that as they left the ship, Basso be given the honors due to a commander.
Basso was a loyal man, a true gentleman, and a stickler for regulations and orders from his superiors. Despite his many disagreements with the government, he remained loyal to it. Many officers were deeply moved when they saw him leave the ship, including Lariño himself, who stood watching from a distance as the vice admiral ordered his flag to be lowered.[1]
Shortly after the fleet's uprising, a Catalina aircraft landed in Puerto Madryn, carrying the officers that Commanders Perren and Rial had sent to take control: Captains Carlos Bruzzone, Mario Robbio, and Luis Mallea; Commanders Raúl González Vergara and Recaredo Vázquez; and Lieutenant Benjamín Oscar Cosentino. Once ashore, they were taken aboard the ships and briefed on the recent developments.
Robbio was appointed Chief of Staff, with Vázquez and González Vergara as his aides. Mallea was named head of the Destroyer Squadron, and Bruzzone was made commander of the 17 de Octubre. Lariño remained as fleet commander, with the other officers continuing in their respective posts.
After ordering the Destroyer Squadron to return immediately to Puerto Madryn, the fleet's command informed the crews that anyone who felt obligated to remain loyal to the national government and did not wish to fight against it could disembark without fear of reprisal. Of the 6,000 personnel aboard, only 85 chose to disembark, most of them conscripts. Two officers, Félix Darquier and Alcides Cardozo, seven petty officers, and two sailors were among those who left the fleet, using a tugboat designated for the task, which picked them up from each naval unit.
The fleet was now in open rebellion. Under these circumstances, it weighed anchor and set off northward, divided into two groups. The main group, led by the 17 de Octubre, headed toward the Río de la Plata, while the remaining destroyers San Luis, Entre Ríos, Buenos Aires, and San Juan set course for Puerto Belgrano.
By midday on September 18, the fleet was sailing north at full speed, maintaining radio silence. Its crew members felt a mix of indescribable emotion and deep confusion. The Navy was heading to battle for the first time in the century, not since the revolution of 1893 and the battle of El Espinillo had they faced such a situation, which carried great significance. It was the moment many had awaited, though something still weighed heavily on them—the conflict was between countrymen, and this deeply affected the sailors' morale. By this point, many lives had already been lost, and many wondered how many more would follow.
Until the night of September 18, no one knew where the Sea Fleet was located. At the time of the uprising, it had been anchored in Puerto Madryn, composed of the cruisers 17 de Octubre and La Argentina; the destroyers Buenos Aires, San Luis, Entre Ríos, and San Juan; the frigates Hércules, Heroína, and Sarandí; the salvage ship Charrúa; and the repair ship Ingeniero Iribas. These vessels were commanded by Captains Fermín Eleta and Adolfo Videla, Commanders Eladio Vázquez, Benigno Varela, Aldo Abelardo Pantín, Mario Pensotti, Pedro Arhancet, Leartes Santucci, and César Goria, Lieutenant Commander Marco Bence, and Commander Jorge Mezzadra, respectively.
Vice Admiral Juan C. Basso commanded the fleet from his flagship, the 17 de Octubre, assisted by Rear Admiral Néstor Gabrielli, commander of the Cruiser Force, aboard La Argentina; Captain Raimundo Palau, commander of the Destroyer Squadron, aboard the Entre Ríos; and Captain Agustín Lariño, commander of the Frigate Division, aboard the Hércules. On the 17 de Octubre, the Chief of Operations, Commander Enrique Gunwaldt, and Captain Raúl Elsegood, Chief of Staff, were also aboard.
The first signal of the uprising reached the fleet at 08:22 on September 16, when Vice Admiral Basso received a communication from the Naval Operations Command informing him of the recent events. Two and a half hours later, at 11:00, rebel officers led by Captain Agustín P. Lariño and Commander Aldo Pantín met aboard the Hércules to initiate the mutiny and take control of the fleet.
As planned, Grunwaldt, supported by Captain Manuel Rodríguez, Communications Chief Captain Félix E. Fitte, and Lieutenant Rodolfo Fasce, moved to the 17 de Octubre with the mission to subdue its commander and Captains Raúl Elsewood and Fermín Eleta. At gunpoint, they were locked in a cabin under the guard of Lieutenant Ricardo Bustamante. Ruiz Moreno recounts that during this time, Lieutenant José A. Lagomarsino ripped out the internal telephone cables, cutting off communication for the loyal elements on board.
Early morning of September 19. The cruiser *9 de Julio* opens fire on the fuel depots at the port of Mar del Plata.(Imagen: gentileza Fundación Histarmar Historia y Arqueología Marítima)
Minutes later, Commander Carlos A. Borzone reported from La Argentina that the situation aboard was under control, as it was on the Buenos Aires, Entre Ríos, and the other ships. On the Buenos Aires, Rear Admiral Gabrielli had been subdued by Captain Videla; on the Entre Ríos, Captain Vázquez had detained his second-in-command and a lieutenant; and on the Entre Ríos, Captain Pantín had done the same with Captain Palau, the head of the Destroyer Squadron.
A confusing incident took place aboard the flagship when Captain Lariño arrived from the Hércules. Suspicious of him, Captain Grunwaldt ordered his arrest, unaware that Lariño was a declared supporter of the revolution, and had him locked in the commander's cabin. Captain Alberto Tarelli had to intervene to clear up the situation, securing Lariño’s immediate release. As Ruiz Moreno explains, Lariño remained aboard the 17 de Octubre as a tactical command officer and never returned to the Hércules.
Before departing, Lariño ordered the transfer of the detained officers to the Ingeniero Iribas, which was docked at Puerto Madryn. Deeply saddened by the situation of his superior, Vice Admiral Basso, whom he admired and respected, Lariño ordered that Basso be given full honors as a commander when he left the ship.
Basso was a loyal man, a true gentleman, and a strict follower of regulations and orders from his superiors. Despite his disagreements with the government, he remained loyal. Many officers were moved when they saw him leave the ship, including Lariño, who watched from a distance as the vice admiral ordered his flag to be lowered.
Shortly after the fleet's mutiny, a Catalina aircraft landed in Puerto Madryn, carrying the officers that Commanders Perren and Rial had sent to take command: Captains Carlos Bruzzone, Mario Robbio, and Luis Mallea; Commanders Raúl González Vergara and Recaredo Vázquez; and Lieutenant Benjamín Oscar Cosentino. Once on land, they were taken aboard the ships and briefed on the latest developments.
Robbio was appointed Chief of Staff, with Vázquez and González Vergara as his aides, Mallea as head of the Destroyer Squadron, and Bruzzone as commander of the 17 de Octubre. Lariño remained the commander of the Navy, with the rest of the officers continuing in their respective posts.
After ordering the immediate return of the Destroyer Squadron to Puerto Madryn, the fleet command informed the crews that anyone who felt compelled to remain loyal to the national government and did not wish to fight against it could disembark without fear of reprisal. Of the 6,000 personnel on board, only 85 chose to leave, most of them conscripts. Two officers, Félix Darquier and Alcides Cardozo, seven petty officers, and two sailors were among those who left the fleet, using a specially designated tugboat to pick them up from each naval unit.
The fleet was now in open rebellion. Under these circumstances, it weighed anchor and set sail northward, divided into two groups. The main force, led by the 17 de Octubre, headed for the Río de la Plata, while the destroyers San Luis, Entre Ríos, Buenos Aires, and San Juan made their way to Puerto Belgrano.
By midday on September 18, the Navy was heading north at full speed and maintaining radio silence. The crew members felt a mix of indescribable emotion and confusion. The Navy was going to war for the first time in this century, having last seen combat during the revolution of 1893 at the battle of El Espinillo, which carried significant meaning. It was the moment many had anticipated, though something didn’t sit right with them—the conflict was between fellow countrymen, and this weighed heavily on the sailors' morale. Many lives had already been lost, and many wondered how many more would follow.
To avoid detection, the fleet maintained complete radio silence, while aboard the ships, some sailors speculated about various possibilities. The worst fear was that, after passing Puerto Belgrano, the fleet might launch a massive attack on Bahía Blanca, Punta Alta, and the rebel bases.
The bridge of the cruiser 17 de Octubre (Imagen: gentileza Fundación Histarmar Historia y Arqueología Marítima)
What concerned the commanders was the inability to establish contact with the River Squadron due to the loss of the communication codes. Without them, any messages would be intercepted and decoded, revealing the operational plan. Two days later, the Sea Fleet reached the "Recalada" pontoon and joined the River Squadron.
Once inside the estuary, the minesweeper Robinson approached the 17 de Octubre, carrying Commander Carlos Sánchez Sañudo, who eagerly boarded the ship to greet his commander, Captain Bruzzone. From the bridge, Sánchez Sañudo called Admiral Rojas, and minutes later, the great cruiser, the flagship of the Argentine Navy, sailed past the Murature with its crew lined up on deck, firing seventeen salvos in honor of the new commander of the unified fleet. Following the cruiser, La Argentina did the same, its crew on deck, while thick plumes of smoke rose from its chimneys. As Ruiz Moreno recounts, "…seventeen crisp cannon shots affirmed the fleet’s subordination to its new commander."
Rojas, filled with emotion, watched the scene from the patrol vessel, accompanied by General Uranga and his senior naval and army officers, living what he described as the most sublime moment of his life and the pinnacle of his career. He was overwhelmed with pride, and the emotion reinvigorated him.
That same morning, with the wind whipping across the decks of the ships, Admiral Rojas boarded the 17 de Octubre, raised his flag on the mainmast, and at 11:45, issued the following statement: "The Sea Fleet has united with the River Squadron. I assume command as Commander-in-Chief." Fifteen minutes later, he announced by radio the blockade of the ports and declared the fleet to be in a state of belligerence.
At 18:00 on September 16, the destroyers San Luis and Entre Ríos entered Puerto Belgrano and docked at the main pier. Nearby, the 9 de Julio was completing its preparations to set sail the following day to join the fleet. By 22:00, the Buenos Aires and San Juan had arrived, followed shortly after by other units.
Aboard the Entre Ríos was Captain Palau, who had been detained and, upon arrival in port, was taken to the Moreno along with Senior Petty Officer Aníbal López, a known Peronist sympathizer. Both were locked up with the other prisoners.
The destroyers unloaded their torpedoes and depth charges and were then resupplied with the appropriate ammunition and provisions. Late into the night, after six hours of intense work, the naval operators finished refueling the ships, while the 9 de Julio was equipped with the necessary ammunition to supply each of the fleet’s units. After testing the machinery, fire control system, and mast antenna, everything was ready for departure. The unit was placed under the command of Captain Bernardo Benesch, with Commander Alberto M. de Marotte as his second-in-command and Commander Raúl Francos as chief of artillery.
The Naval Base at Mar del Plata was also a target of the rebel fleet. (Image: Fundación Histarmar Historia y Arqueología Marítima)
Frigate "Sarandí" (Image: gentileza Fundación Histarmar Historia y Arqueología Marítima)
Frigate "Hércules" (Image: Fundación Histarmar Historia y Arqueología Marítima)
Destroyer "San Juan" (Image: Fundación Histarmar Historia y Arqueología Marítima)
Destroyer "San Luis" (Image: Fundación Histarmar Historia y Arqueología Marítima)
The cruiser La Argentina, flagship of Admiral Rojas until his transfer to the 17 de Octubre in the early hours of September 19. (Image: Fundación Histarmar Historia y Arqueología Marítima)
Destroyer "Buenos Aires" (Image: Fundación Histarmar Historia y Arqueología Marítima)
Workshop Ship "Ingeniero Iribas" (Image: Fundación Histarmar Historia y Arqueología Marítima)
Upon learning that the Navy had gathered in the Río de la Plata, the government ordered an air attack, given the success of the Air Force’s actions against the River Squadron on September 16. As a result, Admiral Luis J. Cornes, the Navy Minister, contacted Commander Crexell to inform him of the decision. The minister ordered Crexell to head immediately to the Morón Air Base, where Avro Lincoln bombers were operating, and where his friend, Commodore Luis A. Lapuente, was waiting to plan the mission.
Crexell was presented with two options: attack Espora Naval Base to neutralize the Naval Aviation units operating against the Army, or attack the fleet itself, a symbol now in the hands of the rebels. Crexell did not hesitate, believing that the fleet posed a far greater threat, especially with its firepower threatening Buenos Aires itself. In his opinion, it was more advantageous to keep the southern base intact and focus on harassing the ships that were endangering the capital.
Crexell and Lapuente met at the airbase, where Lapuente had been studying an attack plan. They agreed that the best course of action was to strike the fleet. They were confident of success because the large ships had ventured too deep into the waters of the Río de la Plata, limiting their maneuverability under attack. A significant development confirmed that the fleet was the right target: the Naval Intelligence Service deciphered codes from Puerto Belgrano, informing the government of the rebels’ communications.
At that time, the rebel radio stations were broadcasting news that the Navy would bomb Buenos Aires at noon, which prompted state-run broadcasters to quickly deny the claim, downplaying the enemy’s strength.
On the morning of September 17, the cruiser 9 de Julio and the destroyers Buenos Aires, San Luis, San Juan, and Entre Ríos set sail, heading directly towards the Río de la Plata. The next morning, Admiral Rojas was discussing matters in the command room with Commander Andrés Tropea when he received an urgent message from General Lonardi, informing him of the dire situation the revolutionary troops in Córdoba were facing.
Recognizing the gravity of the situation, Rojas convened his staff, briefed them, and decided on a show of force to relieve pressure on the rebel positions. It was decided that, if the units in Mar del Plata did not align with the revolution, they would bombard the fuel tanks, the Submarine Base, and the Anti-Aircraft Artillery Regiment at Camet—a measure requested by Puerto Belgrano. At 17:11 on September 18, the cruiser 17 de Octubre sent the following directive to its sister ship, the 9 de Julio: "Destroy the oil and gasoline depots at Mar del Plata, with prior warning to the population." Two hours later (19:02), the Destroyer Squadron received another message: "... destroy the oil tanks at Mar del Plata and bombard the Anti-Aircraft Regiment."
Leading the group, the 9 de Julio changed course and headed toward its targets.
Shortly after receiving the order, an unexpected event created tension aboard the 9 de Julio. Senior Petty Officer Miguel Spera, aware that the fleet would attack Mar del Plata, attempted to incite a mutiny among the crew, attacking an officer. He was shot dead at 22:30, and as his body was removed from the engine room, ten other suspects were arrested and locked in a cabin, heavily guarded by an armed detail.
Almost immediately, another shocking event confused the high command: Captain Bernardo Benesch refused to open fire on Mar del Plata, demonstrating that some still had not fully accepted that they were at war. Benesch declared that he would not shoot and locked himself in his cabin. If that was his stance, he should have spoken up earlier, disembarking at Puerto Belgrano when the command gave anyone who disagreed with the revolution the option to leave. His remaining aboard only to refuse the order at the critical moment indicated mere speculation on his part, and he was ordered to leave the unit immediately.
Commander Alberto de Marotte assumed command, and the attack mission continued as planned.
By that time, the fleet, led by the 9 de Julio, had reached the waters off Mar del Plata. At 21:15, the destroyer Entre Ríos sent a message to the Submarine Base, warning that if they did not align with the revolution, they would be bombed at dawn. The message also instructed that the civilian population be warned and stated that any forces resisting would be attacked. The message further specified the evacuation of the area from Playa Bristol to Playa Grande, extending five blocks inland. "To avoid further destruction, I demand the immediate presence of the director of the Anti-Aircraft School and the commander of the Submarine Force on board. If by midnight, the local radio stations have not broadcast the evacuation order, the Naval Base will be included among the targets to be bombed."
While these events unfolded, the repair ship Ingeniero Gadda and the submarine Santiago del Estero were heading toward the Río de la Plata, the latter commanded by Captain Juan Bonomi, who had left the Mar del Plata Base after the mutiny. Both vessels effectively carried out blockade and surveillance duties, with the submarine engaging when unidentified aircraft appeared.
The incident occurred in the early afternoon while the submarine and repair ship were following Admiral Rojas’ orders to approach Montevideo, issued at 08:50. The Ingeniero Gadda took position near Cabo Polonio, while the submarine moved closer to the designated point. At 13:10, the Santiago del Estero’s radar detected unidentified aircraft, prompting Captain Bonomi to sound the alarms. Five minutes later, he ordered his gunners to open fire with the 40mm Bofors cannon. At 13:20, he sent the terse message: "I have repelled attacks from enemy aircraft." Unable to dive due to the shallow waters of the Río de la Plata, the submarine, now a highly vulnerable target, had no choice but to shoot.
The Santiago del Estero was first overflown by two Uruguayan Air Force planes on a patrol mission, and later by a loyalist aircraft that passed overhead at low altitude. The submarine fired but missed both targets, forcing the first to maintain a distance and the second to turn away toward Buenos Aires without launching an attack. Thus, for the first time in Argentine history, Navy submarines engaged in combat.
"Submarines are particularly vulnerable on the surface; their protection lies in diving, and any minor hull damage could prevent them from submerging, leaving them defenseless against air attacks. The audacity and bravery of Commander Bonomi, commanding the Santiago del Estero, were well-known, and once again, he demonstrated them by venturing into the shallow waters of the Río de la Plata under the threat of government aircraft, where diving was impossible. Repelling air attacks with only a single 40mm Bofors gun was a situation that any naval officer would understand, and I could clearly appreciate the feelings of those with me when I received the brief message," wrote Rear Admiral Jorge E. Perren in his account [2].
On the morning of September 18, Commander Enrique Plater, commander of the Submarine Base, boarded a boat to meet with Commander Miguel Mauro Gamenara aboard the corvette República. He attempted to persuade Gamenara to join the rebel forces, but Plater stood his ground and left to meet secretly with Colonel Francisco Martos, head of the Anti-Aircraft Regiment at Camet, trying to convince him not to resist.
The details of that meeting and another that took place later near the city’s fire station are well-documented in Ruiz Moreno's work. Martos, believing the threat of bombing to be mere bluster, refused to notify the population to evacuate and, suspecting that Plater was a revolutionary sympathizer, attempted to detain him.
The destroyer Entre Ríos was one of the ships that attacked Camet (Image: Fundación Histarmar Historia y Arqueología Marítima)
From the bridge of the Entre Ríos, communication was established with the base, demanding the presence of Plater and his second-in-command, Commander Francisco Panzeri, under the threat of initiating action if they did not comply. This made it clear that neither of the two officers supported the rebels, leading Martos to release them.
Plater and Panzeri returned to the base, observed by numerous Federal Police forces that Martos had deployed along the coast, reinforced by armed civilians from the Justicialist Party. At 03:10, Plater returned to the Entre Ríos, accompanied by Commander Rafael González Aldalur. Half an hour later, he left the ship, deeply saddened by his failure to reach an agreement. He had engaged in a heated argument with Captain Pantín, who harshly criticized him for not preventing bloodshed, leaving Plater confused and unsure of how to proceed.
The Mar del Plata Naval Base was in a grave situation, threatened from the sea by the rebel fleet and surrounded on land by loyalist forces. In a severely demoralized state, Plater asked Panzeri to raise a white flag in surrender and prepare to lay down arms, but Panzeri refused.
At 05:30, Plater convened a meeting with his officers to inform them of the situation. His state of mind was such that his second-in-command, Commander Mario Peralta, forcefully rebuked him, demanding that he act according to his rank and urging him to choose a side. When Plater failed to do so, Peralta took command, declared in favor of the uprising, and alerted the Anti-Aircraft Artillery Regiment and the Federal Police to warn the civilian population of the impending attack. Ten minutes later, the 9 de Julio sounded the call to battle stations and aimed its guns at the target.
At 06:10 on September 19, a Martín Mariner aircraft, returning to Puerto Belgrano after a failed mission to bomb the Dock Sud refineries, made contact with the 9 de Julio, requesting permission to bomb the fuel depots at the port of Mar del Plata. Permission was granted, and the naval aircraft approached the large tanks, dropping its bombs under cover of night before retreating southward.
Although none of the bombs hit their target, the maneuver served to show the local forces that the threat was real. The detonations startled the population, many of whom were still asleep at the time, and some rushed out of bed to see what was happening through their windows. The darkness of the night made it difficult to see, though the glow of flames eerily illuminated the cloud-covered sky above the city.
On the 9 de Julio, orders were being exchanged rapidly. In the Fire Control Center, the Chief of Artillery, Commander Raúl Francos, prepared to open fire as the ship rocked from the heavy waves. At 06:15, Commander De Marotte announced over the loudspeakers that, following orders from Fleet Command, they were preparing to open fire on the first target: the fuel depots in Mar del Plata. He also stated that the destroyers would target the Anti-Aircraft Artillery Regiment at Camet and reassured the crew that the targets were strictly military, with civilians being evacuated by city authorities. He further declared: "The purpose of these actions is to show those who have debased the country, trampling on freedom, laws, and the dearest Argentine values, that the revolutionary forces are determined to eliminate the perpetrators of such infamies. If necessary, we will also attack the port of Buenos Aires."
His final words were meant to raise spirits: "As Argentines, it pains us greatly to fire upon our own, but the blindness of those who have dishonored justice and led us into moral ruin forces us to take this extreme measure. The Nation expects everything from our courage and our strict adherence to duty. Crew of the cruiser 9 de Julio: man your battle stations!"
In addition to this stirring address, Ruiz Moreno recounts the orders sent from the bridge to the information center: with heading 180, speed 5, revolutions 0-5-1, and a distance of 9-1, 9-1, the cruiser entered the sector, and at 07:14, the attack began.
The three guns in each of the five artillery turrets fired a first salvo, shaking the ship. Four more salvos followed, with each turret firing one gun at a time, and all three firing simultaneously from the fourth volley onward. The target was hit directly. Three tanks exploded in flames, sending out thick tongues of fire that lit up the night ominously. Despite the darkness, the lookouts aboard the ship could make out several tanks still intact, prompting a resumption of the bombardment. Another barrage of shells fell on the area, transforming it into an inferno. The explosions created a thick cloud of smoke that began drifting horizontally towards Miramar, carried quickly by the winds.
In the pre-dawn darkness, the civilian population hurriedly evacuated the area under persistent rain.
The fuel depots at the port of Mar del Plata are ablaze after the naval bombardment.
At a distance of 289 degrees and 9,700 yards, the 9 de Julio launched its final attack at 07:23, once again targeting the fuel depots. A total of 68 six-inch shells were fired, destroying nine of the eleven oil tanks and severely damaging the tenth. The shells landed with remarkable precision, within an area 200 meters long and 75 meters wide, with only five shells falling outside that range, no more than 200 meters from its boundary. No civilians were injured.
After 10 minutes of shelling, the 9 de Julio withdrew to provide anti-aircraft cover for the destroyers as they began their operations.
While the fleet was attacking the oil tanks, the Submarine Base was being surrounded by loyalist forces from the Federal Police, Anti-Aircraft Artillery Regiment troops who had positioned their 40mm Bofors cannons on the hills surrounding the golf course, and heavily armed Peronist civilians. As a result, Commander Peralta, acting commander of the base, urgently requested support from the Destroyer Squadron for artillery cover: "I estimate I am about to be attacked. Request artillery support." The response came quickly.
-"I will provide fire support immediately. You must designate a ground spotter and establish a link on channel GAS-1."
The destroyers
Entre Ríos,
Buenos Aires, and
San Luis, supported by the corvette
República, began their approach at 12 knots, precisely as the
9 de Julio ceased firing. On the
Buenos Aires, Commander Eladio Vázquez ordered the Chief of Artillery, Lieutenant Gonzalo Bustamante, to open fire.
The Anti-Aircraft Artillery Regiment at Camet became a target of naval fire. (Image: Mar del Plata's newpaper "La Capital", Family Album http://www.lacapitalmdp.com/contenidos/fotosfamilia/fotos/8054)
Submarine ARA "Santiago del Estero" (S-2) (Image: Fundación Histarmar Historia y Arqueología Marítima)
Destroyer "Juan de Garay" (Image: Fundación Histarmar Historia y Arqueología Marítima)
Guided from the ground by Lieutenant Jorge A. Fraga, the Buenos Aires fired its first shot, which overshot the target. The shell flew over the cemetery and struck Juan B. Justo Avenue (in front of a fishing shop), causing significant damage to nearby buildings. Fraga instructed the gunners to lower the barrels by 500 millimeters, and the second salvo hit one of the artillery pieces threatening the Naval Base from the heights of the golf course. The spotter (Lieutenant Fraga) radioed that the shells had found their target. Encouraged by this success, he ordered the guns to be lowered further for a new volley, which devastated the positions along the bluffs of the golf course, firing intermittently every 10 seconds.
Soldiers and militia members fled in disarray, leaving behind several dead and wounded. The only ones who remained steadfast were the CGT militiamen, who once again showed they were willing to fight to the end. Meanwhile, revolution supporters on Playa Grande waved flags and cheered for the Navy and the nation, unaware of the danger they were in.
Behind the Buenos Aires came the Entre Ríos and San Luis, both sailing in line and firing upon the Peronist positions. Despite the naval bombardment, loyalist Army troops and armed union members continued to fire upon the base installations, even after the shelling ended at 09:30.
A chaotic retreat ensued, as officers and personnel from the Naval Base rushed towards the boats and launches moored at the docks, as well as three fishing vessels that Captain Panzeri had brought in for evacuation. Some sailors threw their weapons into the water to prevent them from falling into enemy hands, while most boarded the boats and set off, coming under fire from Peronist forces on the shore. A firefight broke out between those aboard the boats and those on land, lasting for several minutes.
During the engagement, several boats being towed by launches had their lines cut, leaving them adrift and vulnerable to both gunfire and the rough seas. Amid the chaos, a technical officer, following Captain Peralta’s orders, raised a white flag of surrender, and the exchange of fire began to subside. Minutes later, the Uruguayan consul in Mar del Plata, who had been summoned, sent a message to the Fleet via the Naval Base, informing them that the city had capitulated. There was jubilation on board the ships, and Captain De Marotte took the opportunity to address the crew over the loudspeakers.
The commander congratulated the crew on their success, attributing it to their dedication and enthusiasm in fulfilling their duties, and urged them to continue the fight until final victory. The Navy had suffered no casualties, except for the mutinous petty officer killed earlier, though the Army had, as a shell from the 9 de Julio had destroyed the artillery piece on the golf course mentioned earlier.
The commander of the Destroyer Squadron, Captain Luis Mallea, remained wary of the loyalist forces' surrender. He summoned the commanders of the Anti-Aircraft Artillery Regiment at Camet and the Aeronautics Detachment, warning them that if they did not comply, he would open fire on their installations, in line with Admiral Rojas' instructions from the previous day.
While awaiting their response, Mallea ordered a Marine platoon, under the command of Commander Carlos López, to land and secure the Submarine Base to reinforce its defenses. To support the operation, the Buenos Aires slowly entered the port, heading toward the submarine docks, while civilians loyal to the revolution waved flags and cheered from the shore despite the heavy rain.
In the northern sector, off the coast of Camet, the destroyers Entre Ríos and San Luis, along with the corvette República, prepared for action as the summoned Army commanders remained silent, and rumors circulated that the feared Tandil Artillery Regiment was advancing toward the city.
At 11:00 on that tense September 19, the Navy ships took up positions and opened fire from 6,000 meters away, launching 175 shells that destroyed the regiment's installations, including the water tank supporting the radar antenna. Several buildings were set ablaze, but fortunately, there were no casualties, as the troops had been evacuated to the nearby town of Cobo less than an hour before, leaving the facilities empty.
The attack ended at 11:30, and the ships headed toward the port, led by the San Luis, sailing under a leaden sky and over choppy waters. As they approached the port, they encountered Peronist civilians who had arrived in several trucks and launched an attack on the base.
A violent firefight erupted, which ended when, near Playa Grande, the destroyers fired their 40mm Bofors guns, supported by naval personnel onshore using repeating rifles. The civilians, heavily harassed, withdrew in different directions, dragging some of their wounded with them.
The destroyers requested reinforcements from the 9 de Julio to bolster the positions defending the base. The commander relayed the request to Admiral Rojas, who authorized it, adding that once the operation was complete and calm had been restored, the fleet should head north to rejoin the main units in the Río de la Plata [3].
With the San Luis stationed off Playa Grande and the Buenos Aires patrolling the port’s approaches, the 9 de Julio drew closer to the coast, as sporadic gunfire continued to echo. Two of the requisitioned fishing vessels approached the cruiser on the port side to receive a company of Marines, consisting of five officers and 120 men, who were immediately transported ashore to secure the base and surrounding areas.
After the Peronist militias were subdued and repelled, Mar del Plata was secured without further complications. An hour later, the four destroyers and the 9 de Julio set course north to rejoin the Sea Fleet, which was poised to engage La Plata and even Buenos Aires itself.
By that time, at the mouth of the great estuary, Admiral Rojas, General Uranga, and their staff transferred to La Argentina, anchored at the Recalada pontoon off Punta Indio. The flagship, the 17 de Octubre, had been dispatched to lead Task Force No. 7, which was tasked with attacking the Dock Sud refineries. Despite the low clouds, rain, and strong winds making operations difficult, the fleet command feared that the Air Force would launch harassment raids from Morón at any moment, so it was imperative to begin the operation as soon as possible.
In a torrential downpour, amid thunder, lightning, and rough waters stirred by the strong late-winter winds, Task Force No. 7 set course for its target, with precise orders to commence operations at 13:00 sharp.
At 11:26, Commander Carlos Sánchez Sañudo sent a message to the loyalist authorities, urging the government to warn the population via the official radio stations that the attack was imminent and that precautions should be taken to protect them. He added that any official who failed to comply with this directive would be judged as a war criminal at the end of the conflict.
As Ruiz Moreno recounts, the Naval Operations Command on land acknowledged receipt of the message, but the government radio stations remained completely silent.
Puerto Belgrano. Communications Echelon (Phots: Miguel Ángel Cavallo: Puerto Belgrano. Hora Cero. La Marina se subleva)
Command Central . Puerto Belgrano (Photos: Miguel Ángel Cavallo: Puerto Belgrano. Hora Cero. La Marina se subleva)
Radar Control. Base Naval Puerto Belgrano (Photos: Miguel Ángel Cavallo: Puerto Belgrano. Hora Cero. La Marina se subleva)
Cruiser "17 de Octubre", (then renamed "General Belgrano"), Admiral Rojas's leading ship (Image: Fundación Histarmar Historia y Arqueología Marítima)
The cruiser "9 de Julio" leaves Puerto Belgrano (Image: Fundación Histarmar Historia y Arqueología Marítima)
Cruiser"9 de Julio", "17 de Octubre"-twin sailing towar open waters (Image: Fundación Histarmar Historia y Arqueología Marítima)
"17 de Octubre" Machine Room (Image: Fundación Histarmar Historia y Arqueología Marítima)
Comercio del barrio portuario en Mar del Plata alcanzado por un proyectil naval (Imágen: Nair Miño, Diario "La Capital" de Mar del Plata, Álbum de Familia [http://www.lacapitalmdp.com/contenidos/fotosfamilia/fotos/8054])
Notes
- The vice admiral considered it a humiliation that the flag was flying on the mast of a rebel ship.
- Jorge E. Perren, Puesto Belgrano y la Revolución Libertadora, p. 197.
- That was the moment when the infantry forces disembarked.
VCA Palmaria conducting maneuvers during training.
