German cruise ship Mein Schiff 2 (My Ship 2), operated by travel giant TUI, set sail on Friday night from the northern city of Hamburg for a three-day round trip in the North Sea, EDNews.net reports citing Deutsche Welle.

The vessel is carrying around 1,200 passengers, compared to its usual capacity of 2,900.

The company had said 1,740 would be allowed to travel, but that quota was not reached.  

Guests will spend the weekend at sea with no stops on land, eventually returning to Hamburg on Monday morning.

Passengers will be required to observe strict physical distancing and hygiene measures on board. They were required to fill out a health questionnaire before boarding, and will not be allowed to serve themselves food at the buffet table.

"It's basically a pragmatic solution where companies are trying to adapt processes to the new situation and get the business going again," Alexis Papathanassis, professor for Cruise Tourism Management, told German magazine Der Spiegel.

"But now is not the time for a hasty reaction," he warned. "Such process changes, hygiene protocols and contingency plans have to be developed systematically and professionally, be transparent and be tested," he said, stressing that "customers must not be used as test objects."

Also, the expert underlined, "a cruise that mainly consists of sea days and social distancing does not correspond to what I consider an attractive holiday experience."