I've surfed most of my life all over Australia and various other countries and rogue waves, sneekers in surf lingo, are often encountered. Of all the places Margaret River on the Aus. sth/west coast is possibly to most imfamous in this regard. Seen some big buggers there, some close up.

On the hand, while sailing/racing last Satdy on Sydney Harbour I encountered a set of three monsters [for the harbour] which were possibly 4ft/6ft and very close together. Caught me by the bows and the ensueing series of nose dives caused my spi pole to bend when the sock filled with water. I had just turned for the run/reach home of a marathon and could only use the kite running square. Bugger.