A very sad day. The World has lost a great man, a great intellect and a great visionary. I think Stephen could have single-handedly solved most of the World’s problems. I wish our current World leaders had 1/100th of the integrity, humanity, intellect and vision of Stephen. If that was the case, the World would be in a much better place. Just some thoughts from my own personal interaction with Stephen. Stephen was always so generous with his time. I remember having email conversations with him about things like ocean plastic removal and Flettner rotors for ship propulsion. When I say email conversations, it was more Stephen enlightening me. On another occasion, I was working with Alfred Cotten during his PhD studies (I hope Alfred doesn’t mind me mentioning him). Anyway, Alfred did some very nice numerical hydrodynamic modelling of a spine of Salter Ducks. Stephen really liked this work and I remember being so happy for Alfred. You know you have made it when Stephen praises your work! Thank you Stephen for everything!