Zac's competitive rowing career started when he began at the King's School in Worcester in 1997. Initially too young to row, he offered his services as a coxswain until he was able to sit in a crew boat.

It was soon apparent that Zac had a talent for the sport as his first few 'lucky' wins laid the foundations for a successful six year winning streak, spanning the remainder of his time at school. Whilst at King's Worcester Zac enjoyed success at regular domestic events, the National Schools and National Championship regattas as well as collecting numerous medals at International regattas as a Junior member of British Rowing.

In 2005 Zac was selected to join the British Under 23 squad and proceeded to win the U23 World Championships in Amsterdam. Just 3 weeks later, Zac was invited to attend the Senior World Championships in Gifu, Japan. Although not a fully fledged member of the Senior squad and at only 20 years of age, Zac achieved a spectacular silver medal, only a short distance behind Greek sculler, Vasileios Polymeros, an Olympian and World Champion with a long standing International rowing career.

2006 brought more success for Zac, as he joined British Rowing's Senior Squad and won the World Championships in front of a home crowd at Eton in spectacular style, setting a new World Record in his wake and asserting himself as a truly outstanding young athlete. After winning each of the three World Cup regattas throughout 2008, Zac and his rowing partner Mark Hunter, were seeded first for racing at the Beijing Olympics. Refusing to disappoint, they gained the coveted Olympic title in what is generally regarded as the Blue Riband event for Lightweight sculling and set a new Olympic record as an aside.

Due to an unfortunate illness throughout the early part of 2009, Zac was unable to train as he had previously and it was decided that he would not compete Internationally for the rest of the season. Whilst this was an inevitable blow following such a superb year previously, Zac's natural determination and desire to succeed again motivated him to focus all of his energy on a speedy recovery. He began the current season with a bang, winning the National Trials in his trademark style and is currently training for the 2010 World Championships at Lake Karapiro, New Zealand.