The Marion Island Relief Voyage was conducted on the SA Agulhas II Voyage 045 between 9 April and 12 May 2021. The 2021 Marion Relief Voyage 045 offered the 9th opportunity to conduct multi-disciplinary, ship-based oceanographic research on board the SA Agulhas II en-route to, from, and around, the sub-Antarctic Prince Edward Islands. Due to the world wide Covid-19 pandemic and the subsequent measures implemented by the South African government to contain the spread of the Covid-19 virus in South Africa, the main ship-based research objectives normally associated with the Marion relief voyage (as submitted through SANAP3 applications) were, like in 2020, once again curtailed. Thus, not all the approved NRF-funded SANAP projects could be accommodated. Similarly, annual ship-based research and monitoring conducted by the Oceans & Coasts Research Branch of DFFE was similarly substantially reduced. This was mainly due to the number of participants allowed to participate on the voyage...