Until recently, most historians shared a prejudice in favour of the history of land, territory and their human inhabitants. Yet two-thirds of the world’s surface is water and much of human history has been conducted on its shores, around its seas and across its oceans. This article proposes reimagining the history of the world through its oceans and seas and examines the multiple genealogies of oceanic history, Mediterranean, Pacific and Atlantic among them. It argues that these models do not exhaust the potential for an oceanic history of the world. It takes the example of the Atlantic and its history to show how models from other oceanic arenas can help us to open up new histories, of regions within larger oceans, of the transnational connections between oceans and of the world beneath the waves.