.jpg)
The vast, dark expanse of the ocean has always been a realm of mystery and danger, especially during wartime. Submarines, those silent predators of the deep, have been integral to naval warfare for over a century. But despite their stealth, their power, and their capability for destruction, there is one particular type of battle that remains almost mythic—an underwater clash between two submarines. And yet, against all odds, such a clash did occur, and it remains the only recorded instance of submarines engaging in direct combat beneath the waves.
This rare and dramatic confrontation happened in the waters of the Pacific Ocean during World War II, between two opposing submarines: the USS Sealion (SS-195) of the United States Navy and the I-124 of the Imperial Japanese Navy. On September 24, 1944, these two submarines would find themselves locked in a deadly underwater duel—one that would take place in complete secrecy, far from the prying eyes of the surface world, and the outcome would be both a testament to the power of these silent machines and an eerie reminder of the dangers that lurk beneath the ocean's surface.
The Setup
The stage for this historic encounter was set during the fierce and ongoing struggle between the United States and Japan in the Pacific theater. Both nations had developed highly capable submarine fleets, and each had been using them to devastating effect in the war. The U.S. Navy's submarines had inflicted heavy damage on Japanese merchant and military ships, while Japan’s submarines, like the I-124, were tasked with similar objectives against the Allied forces.
The USS Sealion, a Balao-class submarine, was well-equipped for the war in the Pacific. She had already completed several successful patrols, sinking multiple enemy ships, and was on her 11th war patrol when she encountered the Japanese I-124. The I-124 was a Japanese Kaidai-class submarine, known for its size and range, making it a formidable opponent in battle. The I-124, like most Japanese submarines, was engaged in attacking Allied merchant convoys and military vessels.
As fate would have it, on that fateful day in September 1944, the two submarines found themselves in the same patch of ocean, unaware of the other’s presence at first.
The Duel
What makes this clash so unique is that it wasn’t a conventional surface battle with ships firing at each other or aircraft bombing targets. Instead, it was a desperate underwater confrontation in complete silence and darkness, a battle where stealth, timing, and luck played as much a role as skill.
The two submarines were approximately 400 miles off the coast of the Philippines when the encounter occurred. The USS Sealion had been patrolling the area, hoping to spot and sink a Japanese merchant ship or warship, while the I-124 was also on the lookout for enemy vessels. The Sealion first detected the I-124 using sonar, identifying her as a large enemy submarine. The Sealion’s crew, knowing that they were in the presence of a powerful enemy, decided to engage.
The battle took place at a depth of around 300 feet below the surface of the ocean. Both submarines were armed with torpedoes, each capable of devastating damage. But it was the stealthiness of the submarines and their ability to hide in the depths that would make this battle all the more intense.
The USS Sealion launched the first attack, firing torpedoes at the I-124. However, the Japanese submarine quickly evaded the shots, diving deeper into the depths and using its superior maneuverability to escape the American submarine’s initial strike. But the Sealion wasn’t finished. After missing with the first volley, she repositioned herself and launched another set of torpedoes, this time hitting their mark.
The torpedoes struck the I-124 with devastating effect. The Japanese submarine was severely damaged, and her crew was forced to abandon ship. The I-124 had suffered a catastrophic hit, and it would be sunk soon after by the very torpedoes she had avoided earlier. The battle, which lasted only a few minutes in real time, would prove to be the only instance in history where two submarines clashed and exchanged fire underwater. In the blink of an eye, one of the most formidable threats to the Allies was neutralized.
The Aftermath
The clash between the USS Sealion and the I-124 was more than just a battle between two submarines. It was a symbol of the brutal, silent warfare that had become a hallmark of the Pacific Theater. Submarines, operating in the dark abyss of the ocean, had turned the waters into a ghostly battleground, where a single hit could spell doom for a vessel and its crew.
The USS Sealion’s crew, while victorious, knew that their triumph was part of a larger, more complex war. The sinking of the I-124 was significant, but it was just one of many victories for the Allied submarine fleet. However, the event would be remembered for its uniqueness. No other direct submarine-to-submarine battle had been recorded during World War II, and it remains a rare historical moment.
For the Japanese, the loss of the I-124 was a blow to their already struggling navy. Submarines like the I-124 were key to Japan’s attempts to weaken Allied supply lines and disrupt their naval operations, but this encounter demonstrated just how vulnerable even the most advanced submarines could be when faced with the superior technology and tactics of the American fleet.
Why This Battle Was So Rare
The rarity of this clash between submarines can be attributed to several factors. For one, submarines were primarily designed to operate in stealth, avoiding direct confrontation when possible. The underwater environment is a challenging battlefield, and while submarines had powerful weapons, direct combat was far from their preferred mode of operation. Instead, submarines typically relied on stealth, waiting for the right moment to strike—often from a distance, when the enemy was unaware of their presence.
Moreover, the technology required for such an underwater duel to occur was still in its infancy. The sonar systems, torpedo guidance systems, and communication methods available during World War II weren’t always accurate enough to ensure a direct confrontation. Submarines operated primarily in isolation, often in silence, which made it extremely rare for two subs to engage in close combat.
Today, underwater submarine battles are even rarer, given the advancements in submarine technology and the advent of stealthier, more sophisticated detection systems. The legacy of the USS Sealion’s clash with the I-124 is a reminder of how even in the depths of the ocean, where silence reigns and shadows move swiftly, the threat of deadly conflict remains.
While there have been other submarine engagements during the war, none have matched the sheer rarity and uniqueness of this historic encounter. It stands as the only recorded underwater submarine clash, a silent battle fought in the depths of the Pacific Ocean, forever etched in the annals of military history.