Thomas Sjöblom and his wife were out sailing on Sunday afternoon at the southern end of Askö in Trosa. Then they noticed something in the water by the boat.
"We've been out in the lake a bit and thought what the heck was that," says Sjöblom.
"Unusual in the Baltic Sea"
It turned out to be a saddle dolphin swimming next to the boat. Something that is not normal, says Kennet Lundin, marine biologist and scientific curator at the Gothenburg Museum of Natural History.
"It is very unusual for them to enter the Baltic Sea. But on the West Coast, it is recurring that they come every summer, says Lundin.
Sjöblom says that the saddle dolphin circled the boat for about ten minutes before it swam on an adventure.
"It was really a cool experience to see when it jumped," he says.
Earlier in May, a killer whale appeared at Hunnebostrand, on the West Coast. But just a few days later, it floated up dead on the beach. The so-called spy whale "Hvaldimir" also became a talking point when it appeared at Hunnebostrand at the end of May.