There weren’t any trees nearby, and the heights of waves given in the nautical version of the Beaufort Scale apply to waves out at sea, not near the shore. So what force would be given for ‘Parked vehicle rocks energetically making items in boot rattle’?
While the blast walloped at my car, I watched the sea: the colour of lead further out, thick with clay close in, capped with muddy foam. Out among the chaotic waves a minute triangle was ripping along the bay. A solitary windsurfer skidded and lurched, making plunging turns at each end of the run. The sail went over once but was soon up again, more and more difficult to pick out through the gathering darkness. It is in this photo somewhere, but I don’t know where.
I hope he is a good swimmer.