Voyages #540 was taken over the Indian Ocean in December 2017. As a young sailor I had to know the Beaufort scale by heart. Going by the appearance of the sea here, the Beaufort scale tells me the sea state is Beaufort number 2, giving a wind speed of between 4 and 6 knots, with the following description: "Small wavelets still short but more pronounced; crests have a glassy appearance but do not break"