Until today (18th of September 2020) I had never seen let alone photographed the type of pleasure craft featured in this image. A search of the Internet reveals that it is a Duotone Sports Echo "Wingfoil". It and another Wingfoil manufactured by a different company were both making the most of the strong Easterly winds blowing across Southampton Water Southampton at the time. The image was captured from the Calshot Castle moat wall.