No. 83: Sep-Oct 1992
September 28, 1991. Aboard the m.v. Staffordshire in the western Mediterranean. On this date, between 0555 and 0810 UTC, observers on the bridge counted 15 waterspouts, one of which was anomalous:
"At 0722 the two spouts furthest forward and the one on the beam dissipated leaving one which was of quite a large diameter, about 20 m as seen at a range of about 300 m. The direction of rotation of the water in the spout was clearly seen. Although the observers were aware that the direction of rotation should be anticlockwise in this case, they decided (with great surprise) that the direction of this particular one was clockwise. The only other spout that passed closer, within 15 m, was very weak, but the direction of rotation at the surface was clearly anticlockwise."
(Edwards, R.A.F.; "Waterspouts," Marine Observer, 62:113, 1992.) All Northern Hemisphere waterspouts should rotate anticlockwise.