A 15-meter humpback whale has stranded for a second time on a sandbank in Wismar Bay after being freed from a similar situation at Timmendorfer Strand.Marine experts from the German Ocean Museum and Greenpeace are monitoring the mammal, which is currently suffering from a skin disease and a lack of proper nutrition.Rescue teams previously used an excavator to dig an escape channel for the animal, but its survival now depends on navigating hundreds of kilometers back to the Atlantic.