As the 184-metre-long tanker was docking in Novorossiysk, Le Meur was on the ship’s bridge overseeing the final approach. Suddenly, the ship’s warning signals started blaring. “As soon as the GPS lost the signal, we had tons of alarms,” he says. “You cannot miss it. Pretty much everything on the bridge started raising alarms.”
Instead of displaying Atria’s actual position, the ship’s systems located it 25 to 30 miles away – at Gelendzhik airport. GPS disruptions aren’t uncommon, Le Meur says, but most of the time when problems happen they’re limited to a few hundred metres.
“In my entire career, it’s my first time I have experienced such a big discrepancy.” To be sure of the failure during the incident in June, the crew restarted both the main GPS and the backup unit, only to find both systems still gave the same incorrect positioning data.
https://www.wired.co.uk/article/black-sea-ship-hacking-russia