The ocean is usually a place of muffled thuds and deep vibrations. But when a Mark 48 ADCAP torpedo hits its mark, the world above the surface stops being quiet. Recently, the US Navy reminded everyone exactly what a heavy-weight torpedo does to a surface vessel. During a SINKEX (Sinking Exercise) in the Pacific, a decommissioned vessel—often used as a stand-in for adversarial threats like those from the Iranian Navy—wasn't just hit. It was launched.
The ship didn't just take on water and slowly slip beneath the waves. It practically jumped out of the sea. This wasn't some Hollywood explosion where a boat bursts into a fireball. It was a demonstration of physics so violent it redefined what most people think they know about submarine warfare. Since World War II, the US hasn't had to sink an enemy warship with a submarine in actual combat, but this exercise proves the capability hasn't gathered any dust. If you liked this post, you should read: this related article.
If you're wondering why the Navy spends millions of dollars to blow up its own old ships, you're looking at the wrong part of the equation. It's not about the target. It's about the message sent to every hostile navy currently trying to challenge international shipping lanes.
Why torpedoes are more terrifying than missiles
Most people think of Harpoon missiles or Tomahawks when they imagine naval combat. Missiles are flashy. They fly fast and hit with a bang. But a missile hits the "skin" of a ship. It starts a fire, it wrecks the bridge, and it might kill the crew. It rarely sinks the ship instantly. For another perspective on this development, refer to the recent update from Al Jazeera.
A torpedo is different.
The Mark 48 doesn't actually try to hit the hull. It's smarter than that. It uses sophisticated sensors to swim directly under the keel of the target vessel. Once it's perfectly centered under the ship's "spine," it detonates. This creates a massive gas bubble that lifts the entire ship out of the water. For a split second, the middle of the ship is supported by air while the bow and stern are hanging over nothing.
Gravity does the rest.
The ship’s own weight snaps its back. Then, as the bubble collapses, a high-pressure jet of water shoots upward, punching through the weakened hull like a freight train. The ship doesn't just sink; it's structurally deleted. That’s why the footage of the recent SINKEX looked so jarring. Seeing a multi-thousand-ton warship lurch upward into the air is a visceral reminder that underwater "stealth" is the most lethal form of sea power.
The Iranian Navy connection and the shadow of the Persian Gulf
While the Navy won't always name a specific adversary during these tests, the timing and the choice of targets scream a specific message to Tehran. Iran has spent decades building a "mosquito fleet" of fast-attack craft and retrofitting older frigates to harass tankers in the Strait of Hormuz. They bet on the idea that the US wouldn't want to risk a billion-dollar destroyer in the shallow, crowded waters of the Gulf.
But a Virginia-class submarine doesn't need to be seen to be effective.
By demonstrating that a single torpedo can vaporize a ship of that class, the US is telling the Iranian Revolutionary Guard Corps (IRGC) that their surface fleet is essentially a collection of floating targets. In any real-world escalation, those Iranian warships wouldn't even know they were under attack until the moment their keels snapped.
We saw a version of this during Operation Praying Mantis in 1988. That was the last time the US and Iran really went at it on the water. The US Navy crippled the Iranian fleet in a single day. Back then, it was a mix of surface fire and air strikes. Today, the submarine force would likely do the heavy lifting before the surface fleet even got within range.
Keeping the Mark 48 relevant in 2026
You might hear critics say that torpedoes are old tech. They'll tell you that drones and hypersonic missiles are the only things that matter now. They're wrong.
Submarines remain the ultimate "apex predator" because you can't shoot down what you can't find. A drone can be jammed. A missile can be intercepted by a Phalanx CIWS or an AEGIS system. You can't "shoot down" a Mark 48 torpedo once it's locked on. It's a 3,500-pound slug of high explosives and advanced sonar that moves at over 50 knots.
The US Navy has been steadily upgrading the Mark 48 to the Mod 7 Common Broadband Advanced Sonar System (CBASS). Honestly, it's a terrifying piece of machinery. It can deal with enemy countermeasures and operate in the "littorals"—that's the messy, shallow water near coastlines where Iran likes to hide its ships.
The logistics of a SINKEX
Setting up one of these "dramatic moments" isn't as simple as pulling an old boat out and shooting at it. There are strict environmental rules. Every drop of oil, every bit of PCB, and every piece of hazardous material has to be scrubbed from the hull before it's towed out. It has to be sunk in at least 6,000 feet of water and at least 50 nautical miles from land.
The Navy uses these events to gather data that simulators just can't provide. They want to see exactly how modern hull designs hold up against real explosions. They want to know how the shockwave travels through the water. This data goes back into the hands of the engineers who design the next generation of US ships, making them harder to kill.
It’s a cycle of destruction and learning. The footage is great for PR, but the hard data on hull stress is what keeps American sailors alive in a real fight.
What this means for the next naval conflict
If you're watching the news, you know the Pacific is heating up. While the Iranian threat is the immediate focus for many in the Middle East, the big picture is the South China Sea. China is churning out ships faster than anyone else. But history shows that quantity doesn't always beat quality, especially when the quality is hidden under the waves.
The US submarine fleet is the "silent service" for a reason. They don't brag much, but when they do—like releasing footage of a warship being tossed around like a toy—it's meant to make people rethink their aggression.
Don't let the lack of submarine combat since 1945 fool you. The tech has moved light-years ahead. The physics of a keel-breaking explosion hasn't changed, but the accuracy and stealth of the delivery system have. If a warship finds itself in the crosshairs of a US sub, it's already over. The crew just doesn't know it yet.
To understand the full scope of this, look up the specs on the Mark 48 Mod 7. Compare the weight of its warhead to the standard missiles carried by most frigates. You'll quickly see why the torpedo is still the king of the sea. Keep an eye on Navy SINKEX schedules; they usually happen during major exercises like RIMPAC. Watching those videos isn't just about the "cool factor"—it’s about seeing the deterrent in action.
