Oscar is a competitive swimmer who has represented both Team GB and Jersey on the International stage. In 2022, he competed at the European Youth Olympics in Slovakia, placing 5th in the 400m individual medley and won Bronze in the mixed medley relay.
The following year, he continued to better his form by securing Gold in the 200m backstroke at Summer Nationals. He also competed at the Youth Commonwealth Games in Trinidad and Tobago, finishing 5th in the 100m and 200m backstroke, 7th in the 400m individual medley, and reached the final in the mixed medley relay. In 2024, he went on to win two junior finals at the Olympic Trials, qualifying for the European Junior Championships in Lithuania, where he made the 200m backstroke final and placed 20th in the 400m individual medley.