
Courtesy of the Metropolitan Museum of Art, public domain
Drawing of a Dutch Ship: The Tholen (?) by Willem van de Velde I (Dutch, Leiden 1611–1693 London); 1625–93
The initial purpose of the DWIC was to capture Spanish ships carrying goods and silver to Europe. Warships were part of the DWIC fleet, and sometimes formed part of a group of ships travelling together. They were huge ships that stood out of the water with numerous gunports and cannons.
Additional information on the period and merchant trading vessels can be found in the film Broadsides by Docema:
http://www.broadsidethefilm.com/index.php