A 47-year-old Sydney man has died after he fell off his water ski at a race in Moama in south-western NSW on Saturday.

Kevin Vahtrik, a highly-experienced water skier who had competed internationally, was being towed behind a boat on the Murray River in a qualifying round of the annual Southern 80 race in the early afternoon.

Mr Vahtrik lived in Sydney's north west.

At around 2.40pm, witnesses saw him fall into the water and called police and emergency services.

Mr Vahtrik was pulled from the river unconscious but was unable to be revived and died at the scene.