The return of the long-running science documentary strand. Freak Wave. Huge cargo vessels have been disappearing without trace amid reports that they have been sunk by a single, massive wave. For years, scientists have argued that such a phenomenon should occur only once every 10,000 years, but new research gathered from places as far apart as the North Sea and South Africa has revealed a fundamental misunderstanding of the power of the oceans. Producer Zoe Heron : Executive producer Matthew Barrett www.bbc.co.uk/horizon