Hanko underwater park and the historic Hanko Peninsula

The Hanko Peninsula was mentioned in an old Danish sea report from as early as the 13th century. Just off the southern tip of the peninsula is the Hauensuoli area, which has been a sheltered harbour along an old sea route of the archipelago. Passing seafarers have left their mark on both the surface and the underwater landscape.

The wreck park is located off the tip of Hankoniemi Peninsula, east of Tullholmen Island. This island is well known for its hundreds of engravings carved into the rock shore by seafarers waiting for better sailing conditions. These markings date from the Middle Ages to the early 20th century.

Hauensuoli pier and a guide sign. There are guide ropes from the pier leading to the wrecks, e.g. the Cable Wreck.

The wrecks of the underwater park

The park consists of four wreck sites, the oldest of which is simply known as the “Cable Wreck”. This is a 20 metre long wooden-hulled wreck that sank near Tullholmen. Based on the artefacts found within, it has been dated to the mid-17th century. The hull is partially buried but can still be seen on the bottom. A guide rope leads to the wreck from a surface mooring buoy, which is placed near the end of the quay, just off the Hauensuoli area. 

A diver above one of the sides of the Cable Wreck.

A guide rope also runs from the mooring buoy to other sites in the park. The second wreck is the so-called “Kobben Northeast”. This wooden ship has only the stern portion remaining, which is about ten metres long. It is located along the guided dive trail which runs between the Cable Wreck to the third wreck, simply known as the Kobben East. This partial wreck is a flush-jointed (carvel) wooden sailing vessel whose remains measure approximately ten metres in length. This wreck has been a well-known dive site since the 1960s.

The dive park’s fourth wreck is named after the nearby islet of Lilla Ankargrundet. The wreckage lies to the north of the islet and consists of a larger wooden ship that has been broken into several parts. The wreck is believed to be the sailing barque Ajan, which sank in 1890.

One of the wrecks of Hauensuoli Underwater park.

Visiting the underwater park

An anchorage buoy with wind and weight restrictions has been installed in the Hanko underwater park. To avoid damaging the wrecks, it is not recommended for boats to use their own anchor within the park. In addition, boats can also dock at Hauensuoli pier and visitors can explore the island's rock shore engravings.

The Hanko underwater park is one of the sites of the Finnish Heritage Agencys' BALTACAR project, where the accessibility to wrecks has been improved by installing guide signs and ropes.

Cable wreck's 3D model in Sketchfab.

More information about these wrecks, as well as other wrecks in the area, including ancient surface relics can be found from the Cultural environment service window.

How and why are these sites protected?

A wreck is a fixed ancient relic protected by the Antiquities Act (295/1963). This law protects all wrecks and parts thereof that can be presumed to have sunk at least 100 years ago. Although diving to wrecks protected by the Antiquities Act is permitted, it is prohibited to tamper with or dive inside a wreck.

Read more about the wrecks of the Hanko underwater parkin the cultural environments service window (in finnish):


The park can be visiteds by a private boat or with an organised excursion.

Although it is allowed to dive the wrecks freely, they must not be tampered with.

Finnish Heritage Agency's mapservice

N: 6640854, E: 261921 (ETRS-TM35FIN)