Misidentified ships One challenge for researchers is that often sources have mistakes. For example, in developing the Dutch order-of-battle for the Battle of Plymouth, an obvious source is the document published in The First Dutch War, Vol. VI, pages 156 and 157. The ship, Kasteel van Medemblik, commanded by Gabriel Antheunissen, was said to be a Friesland ship. The Kasteel van Medemblik was actually a Noorder-Kwartier Admiralty ship. For disobeying his admiral, Pieter Florissen, and failing to support him at the Battle of Portland, Captain Antheunissen lost his ship, and was replaced by Adriaan Houttuijn.