BERLIN (AP) — A humpback whale that has become stranded repeatedly off Germany’s Baltic Sea coast in recent days got stuck again on Tuesday, authorities said, less than a day after swimming free. But rescuers were hopeful that it could still find its way out into the open sea.

The whale, which is 39-49 feet long, swam free late Monday from the spot near the German port of Wismar where it had been stuck since the weekend. It disappeared from view for hours until it was seen Tuesday morning off an island called Walfisch — as it happens, a dated German word for “whale.”

Police and the environmental group Greenpeace sent rubber boats to accompany the whale, but it turned off a course that would have taken it out of Wismar Bay and into an inlet, where it was stranded again, said Till Backhaus, the environment minister of Mecklenburg-Western Pomerania state.

Rescuers were at least able to prevent it from swimming far into the inlet, and it is once again in deep enough water that it could swim off under its own steam, Greenpeace marine biologist Thilo Maack said at a televised news conference.

An effort last week to rescue the whale from a shallow underwater sandbank at Timmendorfer Strand, a resort town over 30 miles from its current location, eventually succeeded with the help of an excavator.

But the apparently exhausted whale was soon in trouble again, albeit in somewhat deeper water. On Tuesday, officials were again banking on giving it peace and quiet to gather enough strength to swim away, and possibly approaching it with boats to motivate it to set off.

The drama captivated Germans, with media sending detailed updates on its progress.

Even if it swims off again, the whale is still far from its natural habitat.

“Our aim is (for it to get) out of Wismar Bay, into the Baltic Sea, through Danish waters into the North Sea, and then into the Atlantic where the whale belongs,” Maack said. “These animals are designed for depths that are beyond anything found anywhere in the Baltic Sea.”

The whale was first spotted swimming in the region on March 3. It is not clear why the whale swam into the Baltic Sea.