A note on the set-up under the Draupner wave

The Draupner wave is the most famous ‘freak’ or ‘rogue’ wave observation. In this note we examine the short-term probability of this event in both following and crossing sea-states. We run random simulations and generate both second- and approximate third-order statistics. The wave is found to be more probable in a following sea. The measured waves showed both a set-up (under the giant wave) as well as set-downs under other large waves in the record – this is found to be consistent with a crossing sea.