He was a nine-time Queensland state representative, an eight-time Australian national champion, a dual Olympian and won a silver medal at the 1999 World Rowing Championships.

He made his first Queensland state appearance in the 1994 youth eight contesting the Noel Wilkinson Trophy at the Interstate Regatta within the Australian Rowing Championships.

In 2000 Karrasch contested and won the President's Cup - the Interstate single sculls championship as the Queensland state representative.

A few weeks later in that same double with Martin Inglis he raced at the 1994 Junior World Rowing Championships in Munich and won a bronze medal.

Karrasch was in the stroke seat for their heat win and they showed great form in the final into a tough headwind taking the silver medal behind the Italians.

At Sydney 2000 with Hick setting the pace this time, they won their heat and looked comfortable in the semi-final until with 500 m to go they were unable to match the final sprint in a very tight race.