This briefing provides a detailed analysis of the available data on migrant deaths and on attempted crossings in the three trans-Mediterranean routes and the Western Africa/Atlantic Route in the first six months of 2021. Migrant deaths on maritime routes to Europe have more than doubled in the first six months of 2021, compared to the same period in 2020. In the first half of 2021, the Missing Migrants Project recorded the deaths of 1,146 people. However, many more are presumed to have died, given the multiple posts in social media of families looking for their loved ones and reports by NGOs indicating possible invisible shipwrecks. Meanwhile, migrant interceptions at sea by North African authorities also increased in the first six months of 2021, compared to the same period in 2020. The briefing highlights the ongoing data gaps on irregular maritime migration to Europe. Better data can help states urgently address their commitments under Objective 8 of the Global Compact for Migration to “save lives and establish coordinated international efforts on missing migrants.” There is an urgent need for States to increase search and rescue efforts, establish predictable disembarkation mechanisms and ensure access to safe and legal migration pathways.