We are a land animal. But millions of us have taken to the sea to live, fight, travel, eat, escape and seek fame and fortune. I am obsessed with the sea. On how humans have built ever more efficient and capable ships to exploit its riches and opportunities. This is an conversation I’ve been longing to have. David Abulafia has written massive, beautiful, scholarly books about the oceans and his most recent, The Boundless Sea, is a masterpiece. He and I chatted about why and how humans have taken to the sea in ships and why what happens on the water affects politics, economics and societies on the land.