Yeah, have had the pleasure of enjoying freak waves a few times out on the Yak. Just the other day I was watching a bar trying to pick the channel so I can reenter… was looking okay, glance behind me back to sea to see a wave at least twice the height of the previous biggest breaking mere meters behind me. Just managed to turn and face it in time … the following wave was also of good size. Went a bit further out but eventually decided the bar was to confused so landed on the beach instead.
Also remember a larger wave washing over everyones gear at the kaikoura surf comp one year, I wisely had moved my gear further back about 20 minutes before it hit