Cannonside Wreck

Any observations about the wrecks or park facilities: or +358 44 920 1647 (sms)


Orthogonal image from video based photogrammetry 3D model at

The Cannonside wreck is a small but interesting dive site in about 10 to 14 meters depth. The site covers only about an are, but it’s very rich in features. The visibility on the site is usually fairly good, thus on a bright day, it can be dived without additional lights.

Most likely, this site consists of a hull fragment of an 18th century warship. The hull fragment seems to extend from the bottom of a ship all the way to its gunwale. Since the fragment must have left at least 5 to 6 meter wide opening on the ship’s hull, it’s a great mystery as what happened to the rest of the ship?

The wreksite is oriented so, that the futtocks or bottom timbers are pointing northward and the gunwale side lies to the south.By diving very close to the ground, it’s still possible to view the remaining bottom/board planking below the futtocks. Common sealing has more or less disappeared (if there ever was any) below the anticipated main battery deck but has preserwed quite well above it.

Several big and small knees can be found on the site, indicating that the ship was a two decked warship. The smaller dagger knees would have been below the (lower/main) battery deck and the bigger hanging knees would have supported the upper deck. Two battery deck gunports can be observed in the middle of the hull fragment and a small (upper deck) one on the south side on its gunwale. Just about a meter to the west from the upper deck gunport, lie the remains of a jeer bitt, with pulleys still intact.

A dive slate (PDF) depicting the wrecksite and naming identified constituents

On the south-western corner of the site, a gun port lid can be found beneath a gun carriage’s axle with a wheel still attached. A main gun -possibly a 36 pounder- with a carriage intact, lies upside down on the west side of the wreck. Around it lie the fragments of another gun carriage, but a second cannon is missing.

There are some rumours around unauthorized salvage of a gun a few decades ago. Other than that, the site seems to be more or less in original state, albeit it has been frequently dived on for several decades now. The site is conpact enough to fit on a dive plate at once, hence no guided tour into it has been arranged. Enlarged copies of the dive plate are displayed near where the guide lines from mooring and diving buoy meet the wreck.

Next step in the maritime archaeological research of the site would be the dendrochronological dating of the main timbers and finding clues of the maker and owner of the Cannon. Both typically require the use of somewhat destructive methods, so professional assessment and well secured funding is needed before initiating the research.


The Sketchfab window embedded below, presents a 3D model of the wrecksite, based on which the above depictions and illustrations were created. The images were extracted from SONY 4k video and Agisoft Photoscan was used for photogrammetric modeling.

by Mopsi
on Sketchfab


More information (in Finnish) may be found at or from the Finnish Heritage Agency.