Iran teases ‘secret’ underwater weapon as Khamenei warns US amid Gulf tensions

Iran’s Supreme Leader Mojtaba Khamenei on Thursday (April 30) signalled a more assertive posture in the Gulf, even as fresh military messaging from Tehran hinted at new capabilities beneath its waters.

In a message marking National Persian Gulf Day, Khamenei said a “new chapter” for the Gulf and the Strait of Hormuz was taking shape amid the ongoing conflict involving the United States and Israel. He added that the region would have a “bright future” without a US presence, according to state TV.

Khamenei issues sharp warning

In his written message, Khamenei said Tehran would secure the Gulf region and end what he called “the enemy’s abuses” of the key waterway. He asserted that a new management of the Strait of Hormuz would bring calm, progress and economic benefits to Gulf nations.

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“Ninety million proud and honourable Iranians… regard all of Iran’s capacities, from nanotechnology and biotechnology to nuclear and missile capabilities, as national assets,” he said, adding they would be defended like the country’s land, air and waters.

Khamenei also sharpened his rhetoric, saying the only place Americans belong in the Persian Gulf is “at the bottom of its waters,” warning that foreign forces have no place in the region.

Iran’s naval threat in focus

That messaging coincided with renewed focus on Iran’s undersea warfare capabilities, with officials hinting at a potential “new weapon” as tensions with Washington escalate.

Iran’s Navy Commander Shahram Irani said Tehran would “very soon” strike the enemy with a new system, adding cryptically that it was “right next to them,” fuelling speculation about an advanced underwater platform.

Defence experts believe the reference could be to the Hoot, a high-speed rocket torpedo first tested in the mid-2000s, though Iran has kept most details classified.

“Hoot,” meaning whale in Persian, is believed to be among the fastest underwater weapons. Iran is thought to be only the second country after Russia to field a super-cavitating torpedo, similar to the Russian VA-111 Shkval.

Unlike conventional torpedoes that travel at 60-100 kmph, the Hoot is claimed to reach speeds of over 360 kmph underwater, enabled by super-cavitation technology that creates a gas bubble around the weapon, drastically reducing drag.

This allows it to move through water at extreme speeds, effectively turning the surrounding medium into a low-resistance channel. The weapon is also believed to carry a high-explosive warhead exceeding 200 kg.

Limits of undersea weapon

However, such speed comes with limitations. Super-cavitating torpedoes consume fuel rapidly, restricting their range to about 15 km, roughly half that of conventional torpedoes.

Experts also point to guidance challenges. At such high speeds, noise and bubble interference make accurate targeting difficult, limiting effectiveness in real combat conditions.

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Even if deployed, analysts say heavily defended US aircraft carriers, equipped with reinforced hulls and protected by layered carrier strike groups, are designed to withstand multiple torpedo hits.

Still, the timing of Iran’s military signalling alongside Khamenei’s remarks underscores a broader message: as tensions rise in the Gulf, Tehran is pairing political rhetoric with reminders of its evolving deterrence capabilities in one of the world’s most strategic waterways.