This narrow strait between Tullisaari and Kobben is a protected natural harbour where sailing ships from countries around the Baltic Sea once waited out storms. The sailors killed time by carving their initials or tales of bravery on the rocks, earning the area the nickname ‘Guest Book of the Archipelago’. Some 600 rock carvings dating back to the 17th century remain. Hauensuoli can be reached by charter taxi boat or on a cruise from Hanko.