America's Cup 2017: Sir Ben Ainslie - Olympian charts course for Great Britain to challenge for trophy

It crashes, it bangs, it sets up a banshee scream of wind noise, and it has an ooh-aah factor which stops old ladies walking their dogs on the Portsmouth shore to watch a weird and wonderful man-made contraption skimming at high speed across the water. They are not watching graceful sailing, they are captivated by the image of paceful sailing. Peaceful it ain’t.