The pair, who caught up before setting sail with their rival crews, were both hoping to take home the £10,000 prize in the Artemis challenge – a 50-mile sprint around the Isle of Wight.
The race is the highlight of Cowes Week - the longest-running regular regatta in the world, held on the area of water between southern England and the Isle of Wight known as the Solent.
Following in the footsteps of her grandfather Prince Phillip, who, as Admiral of the Royal Yacht Squadron, is a Cowes Week regular, Zara took her first steps in boat racing competing on the Artemis II.
The 28-year-old royal was joined on board by her boyfriend Mike Tindall.
Bryan took his place among the crew of Artemis The Profit Hunter. He was hoping to raise funds for his Bryan Adams Foundation, a charity that distributes grants for worthy projects around the world.
A crew member reported that before the race had even started, keen sailor Bryan made a beeline for the wheel, enjoying having a 60ft yacht under his control.
But the star's popularity proved to be his downfall, with picture-hunting helicopters circling above taking the wind out of the boat's sails and losing the crew their first place.
Lack of wind forced the organisers to halt the race – and positions taken at the last mark placed Bryan's team third, with BT's crew headed by Ellen MacArthur taking the top spot.