in June, 2017, a French oil tanker, the Atria, sailed across the Mediterranean, through the Bosporus strait, and into the Black Sea. As the ship approached the Russian city of Novorossiysk, the captain, Gurvan Le Meur, noticed that the ship’s navigation system appeared to have lost its G.P.S. signal. The signal soon returned, but the position it gave was way off. The Atria was apparently some forty kilometres inland, shipwrecked at the airport in Gelendzhik, a Russian resort town.