When Oliver Barrand first heard of underwater rugby he was convinced it was a stitch up.

A friend invited him along to a training session, a ploy he thought was part of an elaborate prank.

Next month Barrand will captain the Australian side as it competes in its first World Championships in Colombia.

"I thought she was playing an elaborate prank on me so I thought I'd call her bluff and it turned out that it was an amazingly fun sport," he said.