Captain Jan Coenders commanded the hired fluit Graaf Willem in the Battle of the Gabbard. He was judged to be too inexperienced in war for further service. His luitenant, lt-cdr Hessel Gerritsz Bertson, is mentioned in a retrospective list from 22 November 1653 as commander. The Graaf Willem was a large 26-gun ship hired by the Admiralty of Friesland.