Before they even cross the line the two boats engage in a tense, tactical dog fight known as the pre-start.

Complicated strategy is involved as they jockey for the best position to hit the race track at speed, on their preferred side of the course and right on the gun.

If one boat can force the other into a penalty for infringing one of sailing’s myriad rights of way rules, all the better.

Nerves of steel and consummate boat handling skills are required and it is not uncommon for specialist starting helmsmen to hand over the role once over the line.

They can enter the starting box any time after the five-minute gun and no later than three minutes before the start.