Understanding the distribution and habitat use of marine megafauna species is a prerequisite to their conservation, specifically in remote pelagic ecosystems. Humpback whales have been decimated by industrial whaling, particularly in Oceania, where the population is listed as « endangered » by the IUCN. Humpback whales are known for their nearshore distribution during the breeding season, but their pelagic habitat use patterns remain mostly unexplored. In New Caledonia, satellite tracking of humpback whales has recently unravelled their use of pelagic offshore seamounts. The MARACAS 7 cruises aim to describe the pelagic ecosystem around tropical seamounts south of New Caledonia, and understand the social and environmental drivers of humpback whale aggregations around these peculiar seabed structures. In practice, the MARACAS 7 cruises combine cetacean and seabird observations over transect lines, in addition to oceanographic and acoustic biomass sampling, and micronecton trawling operations.