In preparation of the construction of the Gemini offshore windmill park van Oord contracted ADEDE for an Archaeological and UXO survey of the seabed.
Located 60 miles north of the Frysian island of Schiermonnikoog the Gemini project area is part of important shipping routes to the German harbours. During the first and second World War these routes were extensively mined by both the Germans and the Allies. During the second world war the Allies’ northernmost bomber route led over the Gemini area making the area and cable corridor suspect for presence of aerial bombs, unexploded anti-aircraft artillery shells and aircraft crash sites. ADEDE conducted a Magnetomer and Side Scan Sonar survey of the project area and the cable corridor.


AUV on deck, ready for launch to survey the areas that are too shallow or confined to the use of towed equipment.

hampden mine laying.jpg

The A-MK1 British sea mine, many of which were dropped by aircraft in the Gemini project area, is being loaded.


Sonar image of a wooden shipwreck in the survey area, a new discovery.

After the data have all been interpreted eligible targets will be selected for identification by UXO experts and maritime archaeologists. Any UXO that is found will be removed or detonated by the Royal Dutch Navy. Archaeological objects and structures will be identified, recorded and reported.


Detection technique for finding ferrous metal in soil.


The Autonomous Underwater Vehicle is a robotic vehicle which carries side scan- and multibeam sonar and can be equipped with a towed magnetometer.

Towed side scan sonar

The towed side scan sonar is used for making images of the water bed, usually in deep water and large project areas.

Marine magnetometer

The G882 towed magnetometer system detects ferromagnetic anomalies on and under the sea bed.