In 1652 he commanded the Briar, attending on the army in Scotland, and in January 1652–3, off Newcastle, captured a Flushing man-of-war of 15 guns, which he brought into the Tyne, and which was afterwards fitted for the state's service.
It was at this time that a charge was laid against him of conniving at his men selling some of the ship's stores and victuals, but it seems to have been put on one side as unfounded and malicious.
In June 1653 he brought into the Downs three French ships laden with tar and hemp, and in May 1654, being then in the Adventure, he took three more, on their way from Havre to Rochelle.
In April 1655 he was appointed to the Portsmouth, which he commanded continuously for the next five or six years, for the protection of trade in the North Sea, though on one occasion, in the end of 1658, he stretched as far as the Canaries, and convoyed home a number of merchant vessels.
Whether Sansum left issue is not stated; but the name remained continuously in the navy list well past the middle of this century.