[1] Born in the Russian Empire in 1913, Zak made aliyah to Mandate Palestine, where he joined the Haganah.

On 17 March 1948 future Prime Minister David Ben-Gurion (and at the time the leader of the Haganah) gave the order to create a Jewish naval service.

He remained as head of the Sea Service that became the Israeli Navy until April 1949 when he resigned in order to pursue a career in teaching.

He was also responsible for renaming HaKfar HaYarok in memory of Levi Eshkol after his passing.

In 1986, Zak, together with HaKfar HaYarok, won the Israel Prize for lifetime achievement to education.