Chancellor Angela Merkel officially opened the festival, which includes around 1,500 events, including the famous regatta in which 4,500 sailors from more than 50 countries will compete.
The waters around Kiel will be thick with boats of all descriptions during the week, including military ships and old multiple masters.
The windjammer parade next Saturday is seen as the highlight of the festival, with more than a hundred classic old yachts and 17 motorboats from nine countries take to the sea.
The opening day of the Woche was only slightly marred by the sinking of a small yacht which was hit by a support boat.