English Captain: Thomas Keysar

Thomas Keysar served in the Commonwealth navy, and possibly before that, in the Parliamentarian navy. From 1649 to 1650, he commanded the Royalist prize Leopard's Whelp (10 guns). In 1651, he commanded the Royalist prize Swan (22 guns). In the sources that I have, his activities are not mentioned, and he is not mentioned as serving after 1651. Sources:

1. R. C. Anderson, List of English Naval Captains 1642-1660, 1964
2. R. C. Anderson, Lists of Men-of-War 1650-1700: Part I English Ships 1649-1702, 1966