Israel will add a fourth advanced Dolphin-Class submarine to its naval fleet within the next few days, the commander of the Israel Navy said Tuesday.

“At this very moment, after leaving Germany, the INS Tanin, the Navy and the State of Israel’s fourth submarine, is making its way to Israel,” Vice Admiral Ram Rothberg said at a ceremony for graduates of a naval course. “It can dive deeper, go farther for a longer time and can operate at a level we have not seen until today.”

The impending arrival of the INS Tanin will bolster a submarine fleet has seen dramatic increases in the number and duration of its operational at-sea deployments over the past several years.

According to a senior Israel Navy officer, 58 percent of the submarine flotilla’s time at sea in 2013 was spent in operational deployments, the other 42% having been devoted to training. That marks a dramatic increase from the three previous years, when submarines spent just 36% of their time at sea in operational deployments.

The submarines also conducted 54 special operations in 2013, a similarly sharp increase from previous years. The operations included deployments to the Lebanese coast and unspecified deployments lasting several weeks that took the submarines thousands of kilometers from Israel.

Israel is also scheduled to receive a fifth Dolphin-Class submarine from Germany, the INS Rahav, later in 2014.

The new submarines have engines that don’t require surfacing to acquire new air supplies, effectively expanding Israel’s naval (and, reportedly, nuclear) reach and allowing for more distant and long-lasting operations.

In 2012, the German weekly Der Spiegel reported that Israel’s submarine fleet has nuclear capabilities and that Berlin is aware of this but has opted to publicly remain mum about it in order to avoid having to defend the deals.

The submarines, according to Der Spiegel, are equipped with Israeli-designed Popeye missiles, which can carry a warhead of up to 200 kilograms. The nuclear warheads are produced at Israel’s Dimona nuclear reactor, the report said.

Israel maintains a policy of nuclear ambiguity, neither confirming nor denying that it is in possession of nuclear weapons.