Sailing from UNK, Marthinus Groenewald competes in the the region dinghy circuit. Marthinus's competitive record on SailingSA begins in February 2025. Since then 2 races across 1 regattas have been completed. Marthinus competes mainly in the Miura fleet, alongside races in other fleets. Marthinus's best results include winning the 2025 Mykonos Offshore Regatta in the Miura fleet, as well as the 2025 Mykonos Offshore Regatta in the Miura fleet. Marthinus remains an active competitor in the Western Cape sailing circuit.