Conservationists continued rescue efforts on Friday to guide a humpback whale recently freed from a sandbank off Germany's Baltic Sea coast.

Teams used inflatable boats in Lübeck Bay to escort the whale, which had been stuck near Timmendorfer Beach since Monday, toward deeper waters.

The marine conservation groups Sea Shepherd and Greenpeace said their boats are in the water to try to keep the whale away from the beach.

At times the humpback whale had been heading back towards shallower water, a Sea Shepherd spokesman said.

Using the inflatable boats, the organizations had created a kind of blockade to stop it from returning to shallow water.

The whale had freed itself early on Friday from a sandbank off of Germany's Baltic Sea coast and was heading out of the Bay of Lübeck, a marine scientist said. It had been stuck there since Monday.

No transmitter was attached to the whale because its skin was too badly diseased.