Sailing from UNK, Marthinus Groenewald competes in the the region dinghy circuit. Since February 2025, 2 races across 1 regattas have been recorded for Marthinus. Marthinus's primary class has been Miura, with additional appearances in other fleets. Key performances include winning the 2025 Mykonos Offshore Regatta in the Miura fleet, along with the 2025 Mykonos Offshore Regatta in the Miura fleet. Marthinus remains active in regional dinghy racing.