The Second International Indian Ocean Expedition (IIOE-2) was launched in December 2015 at the culmination of the Indian Ocean Conference at Goa to mark the completion of 50 years of first International Indian Ocean Expedition. The IIOE-2 is a multi-national, multi-institutional programme to advance our understanding of the physical, chemical, biological, geological and climatological aspects of the Indian Ocean to enhance its role on the socio-economy of the region.