Palyam

Palyam (, an abbreviation of "Plugat HaYam" (), lit. "Sea Company") was the sea force of the Palmach.
History.
Palyam was set up in April 1945 as the Palmach's tenth company (Pluga Yud) which originated from the Palmach's Naval Platoon. The Company's first commander was Abraham Zakai. It belonged to the Fourth Battalion which was the Palmach's Staff Battalion, attached to the Palmach's Staff Battalion (the 4th Battalion).
The division was in charge of underwater demolition and maritime activity units. The majority of their activities were related to the escorting of ships of Aliyah Bet, immigration ships (66 of them in all) bringing Jewish refugees from Europe by boat, despite the British White Paper of 1939 limiting Jewish immigration into Mandate Palestine. 
From August 1945 to May 1948, approximately seventy Palyamniks escorted close to 70,000 immigrants in 66 sea voyages, from Sweden in the north to Algeria in the south, France in the west to Romania in the east. They also escorted the arms ships that brought vital arms during the war. 
On the eve of the 1948 Arab-Israeli War, Palyam consisted of approximately four hundred marines, eighty of them were graduates of the marine officers course which was held in the Marine School near the Technion, and seventy of them graduates of the ship commanders course at kibbutz Sdot Yam. 
Headquarters of Palyam was located in kibbutz Sdot Yam, but the unit had installations in kibbutz Neve Yam, Ma'abarot, Giv'at HaShlosha, Shefayim and Yagur.
On March 17, 1948, the Naval Service (the precursor of the Israeli Sea Corps) was formed, and the Palyam were ordered to join. Many of the Palyam members formed the core personnel and command of the Naval Service. In fact, most ship commanders during the first years of the Navy, and up to 1975, most of the Navy's commander-in-chiefs, were Palyam veterans. 
Palyam members who specialized in maritime sabotage formed Shayetet 13, the IDF Naval Commando unit.