In May 1677, he enrolled in the Royal Danish Navy with rank of captain of the first class. He commanded "Norske Løve" in the Battle of Køge Bay on 1 July and was then appointed as Vice Admiral and command of a squadron in the Baltic Sea fleet under Admiral General Cornelis Tromp. He took part in the expeditionary fleet to Öland and lost an eye during the conquest of Borgholm. He then took command of a squadron under Niels Juel, took part in the expeditionary fleet which was sent to Rügen in 1678 and headed the Siege of Kalmar in 1679.