Eight German warships have left for the eastern Mediterranean, where they will join the United Nations peacekeeping mission in Lebanon.
The German contingent will be the second-largest in the UN mission
The ships set sail a day after MPs authorised the Middle East mission - Germany's first since World War II.
Up to 2,400 navy personnel will patrol Lebanon's coast to prevent arms from reaching Hezbollah militants.
But Germany is not sending ground troops to the region because of sensitivities over its Nazi past.
The issue of sending German troops to the region - some 60 years after WWII - has divided the country.
Partly because of concerns that German troops might be drawn into fighting against Israeli soldiers, Berlin has refused to follow other European nations in sending ground troops to Lebanon.
The German contingent will be the second-largest in the UN force of 15,000 after Italy's, which is 3,000 soldiers strong.
It left from the North Sea port of Wilhelmshaven and is expected to reach the Lebanese waters in 10-14 days.
Last week, German Chancellor Angela Merkel described as "historic" the government's decision to deploy warships in the eastern Mediterranean.
In August, a UN-brokered truce ended 34 days of fighting between Israel and Hezbollah.
More than 1,100 people - mostly civilians - were killed in Lebanon during the war. In Israel, more than 150 people - mainly soldiers - were killed.