Sub-Antarctic marine life exhibits unique ecological traits and pronounced endemicity levels. Despite their ecological uniqueness and high conservation value, studies on sub-Antarctic benthic communities are scarce. Using underwater video imagery, we assessed the nearshore diversity and structure of faunal and algal communities of the Crozet archipelago along 12 scuba and remotely operated vehicle transects performed at Baie du Marin and Crique du Sphinx (Ile de la Possession). The influence of habitat types on species distribution was evaluated in relation to the setting up of submarine cables. A total of 51 faunal (mainly represented by Echinodermata and Porifera) and 14 algal (mainly represented by Rhodophyta) taxa were identified. The high habitat heterogeneity found in shallow waters (from 0 to 20 m depth) enhances the species richness and diversity, whereas deeper (> 20 m depth) areas were dominated by large sandy stretches and a lower diversity. Rocky habitats had the highest richness and diversity values, promoting local diversity. Submarine cables act as a hard substrate for species, whose suspended sections influence the composition and structure of benthic communities. This study improves our limited knowledge of benthic habitats and diversity from Crozet and constitutes a baseline for further monitoring of marine communities for conservation strategies related to this part of the French Southern Territories National Nature Reserve.