The Israeli Navy has pulled back the curtain, just slightly, on one of its most closely guarded assets by releasing extremely rare footage from aboard and around its new submarine, INS Drakon. The boat is the latest member of the Dolphin II class, but it looks noticeably different from the ones that came before it. Its length has grown from 68.6 to 73 meters, its hull has been redesigned, and its sail is significantly larger. That extra volume in the sail has fueled talk of vertical launch cells, though their existence has never been officially confirmed.

So what could be hiding in there? According to various assessments, the space could be meant for ballistic or cruise missiles, unmanned systems, reconnaissance equipment, or systems for delivering special forces, and Israel has said nothing to settle the debate. That silence is typical, because Israel's submarine fleet, which now numbers six boats, is one of the most secretive parts of the country's conventional military forces. It is exactly why footage and reports from aboard Israeli submarines are so scarce, and why every new clip gets picked apart by defense watchers. For now, the Drakon's real capabilities stay hidden beneath the surface, and the biggest question is still what that oversized sail is really built to carry.