Israel has took delivery of its fifth German-built submarine, an advanced Dolphin-class vessel said to be capable of remaining submerged for up to a week. Speaking at an official welcome ceremony, Prime Minister Benjamin Netanyahu said the undersea fleet allows Israel “to deter enemies who seek to destroy us.” The new arrival is named “Rahav” after a biblical sea monster.

Israel is the Middle East’s sole of undeclared nuclear power, refusing to confirm or deny it has such weapons. Its five German-made submarines will be used to protect its shores and carry out spying missions against its arch-foe Iran. A sixth submarine is to be delivered in two to three years although defence analyst Yossi Melman, writing in Maariv newspaper, has said it is likely to be cancelled for budgetary reasons.

The current model costs about 500 million euros ($540 million) to build. Berlin is paying one third of the cost itself.

“Rahav will take an active part in defending the state of Israel and its territorial waters, operating deeper, further, and for longer from the very depths — with a watchful eye,” President Reuven Rivlin said at the ceremony.