The INS Tanin – the Navy's fourth and most advanced Dolphin-class submarine – is en route to Israel from Germany.

The INS Tanin, Israel's fourth and most advanced Dolphin class submarine – is en route to Israel from Germany, and the Navy has released video of the vessel and the ceremony in which it was launched at Germany's Kiel shipyards at week's end.

Reports claim Israel has modified the Dolphin's 650mm launch tubes to allow the launch of missiles that could carry nuclear warheads. Such missiles should give Israel the ability to deter belligerent neighbors like Iran, if it delivers a sufficiently convincing threat to make use of them. However – Israel has thus far maintained a policy of nuclear ambiguity.

The German weekly Der Spiegel reported that the submarines have a nuclear capability and are part of Israel's weaponry to counter the nuclear threat from Iran.

German Chancellor Angela Merkel has denied that the submarines have a nuclear capability.

The new Dolphin also has state of the art Air-independent propulsion (AIP) systems, which allow it to operate without the need to access atmospheric oxygen by surfacing or using a snorkel. This makes it virtually silent and potentially stealthier than nuclear powered submarines.

It is the most expensive single vehicle in the IDF's arsenal and unlike the first three Dolphins delivered to Israel, is modeled on the German Navy's Type 212 submarine, and not on the export-only Type 209. The AIP Dolphins are 12 meters longer than the Type 212, are nearly 500 tons heavier in submerged displacement, and have a larger crew.

Israel has already purchased a a fifth Dolphin-class submarine at a subsidized rate from Berlin, and has an option for a sixth.

In May 2012, during an official ceremony in the Kiel shipyards, the German builders transferred the INS Tanin to the Israeli Navy. However, it did not complete its testing process until now.

Each Dolphin-class submarine is capable of carrying a combined total of up to 16 torpedoes and Submarine-launched cruise missiles (SLCMs). The cruise missiles have a range of at least 1,500 km (930 mi) and are widely believed to be equipped with a 200-kilogram (440 lb) nuclear warhead containing up to 6 kilograms (13 lb) of plutonium.

A wet and dry compartment is installed for deploying underwater special operations teams.

Jane's Defense Weekly reports that the Dolphin-class submarines are believed to be nuclear armed, offering Israel both a first strike and a second strike capability. The Federation of American Scientists and GlobalSecurity.org report that the four larger torpedo tubes are capable of launching Israeli built nuclear-armed Popeye Turbo cruise missiles (a variant of the Popeye standoff missile), and the US Navy recorded an Israeli submarine-launched cruise missile test in the Indian Ocean ranging 1,500 km (930 mi).