English Captain: Robert Dennis

Robert Dennis served in the Commonwealth navy. In 1649, he commanded the 2nd Rate George. In 1650, he commanded the hired merchantman Peregrine. From 1651 to 1652, he commanded the John (32 guns and a crew of 120 men). He had Edmund Curtis under his command, in the Guinea frigate (32 guns and a crew of 140 men), and was sent to Virginia in 1652. Robert Dennis apparently stayed in America, as a colonist. If you search for him in Google, you will find more ("Robert Dennis" 1652 john virginia). Sources:

1. R. C. Anderson, List of English Naval Captains 1642-1660, 1964.
2. Dr. S. R. Gardiner, The First Dutch War, Vol.I, 1898.
3. C. T. Atkinson, Ed., The First Dutch War, Vol. VI, 1930. (index)
4. House of Commons Journal Vol.7: 14 January 1652