In the summer of 2020 two identical catamarans sat docked end-to-end in the port of Mahón, Menorca. Blown-up photos of sea creatures plastered along their sides advertised glass-bottom boat tours of the island’s giant natural harbour. I took Hanah (my daughter, then nearly three years old) on one of the tours. She was restless onboard as a distorted voice produced facts in five languages about certain landmarks along our route, including a few small, rocky islets floating in the port. Our boat stopped at the edge of the open sea and we were escorted below deck into one of two cramped viewing compartments, where haunted-looking fish materialized out of the green ether to snap at mud-coloured pellets flung discretely overboard by the crew.