In a surprising security breach, French nuclear submarine crews inadvertently revealed sensitive patrol schedules by sharing their fitness activities on the popular app Strava. Strava, a platform designed to track athletes’ activities through mobile devices, became the unexpected source of a major security leak.

The Longue Island base near Brest, home to four nuclear-armed ballistic submarines, is considered the most secretive installation in the French Navy. These submarines, known as “black boats,” have been on continuous patrol since 1972, always prepared to launch nuclear strikes under presidential orders. The base operates under stringent security protocols, including ID checks, facial recognition, and a strict ban on electronic devices.

Despite these measures, sensitive details about submarine patrols were exposed through the fitness app. An investigation revealed that crew members unknowingly shared their activities on Strava, which made it possible to deduce the patrol schedules of these highly classified submarines. This incident is reminiscent of the 2024 “StravaLeaks,” where global leaders’ movements were similarly exposed due to the app’s open data sharing.

In a parallel incident, bodyguards of French President Emmanuel Macron also revealed his whereabouts by publicly sharing their fitness activities on Strava. This oversight led to unintended broadcasting of the president’s movements.

The data shared on Strava, including descriptions of training sessions, provided enough information to map out the operational schedule of the Longue Island military base Le Monde reports. This information, combined with the duty schedules of the nuclear submarines, posed a significant security risk. Many of the crew members had openly signed their profiles with their real names, making their activities easily accessible to anyone on the platform.

This incident underscores the potential risks of using public fitness tracking apps in sensitive military environments and highlights the need for stricter digital security protocols to prevent similar breaches in the future.

Strava was founded in 2009 in by Michael Horvath (former CEO) and Mark Gainey (Chairman). Its an American company.