The vessel participated in the senior anti-submarine warfare exercise SQUALE, as part of the scenario of conducting an amphibious operation under underwater threat. Escorted by the multi-mission frigate with enhanced air defense capability (FREMM DA) Alsace, the FREMM Auvergne and the air defense frigate (FDA) Forbin, the Tonnerre implemented two fast amphibious landing craft (EDA-R) of the amphibious flotilla. The latter conducted a night raid of several dozen nautical miles to deploy ashore the intervention and protection unit (UIP), a section of the 1er Foreign Engineer Regiment and a team of marines using five Futura.

In addition, during this period at sea, the crew of the Tonnerre conducted various individual training sessions to maintain its operational capabilities, between visiting exercises, disaster fighting, maintaining combat capabilities or shooting. Training was also organized for the benefit of other armies and forces, with aviation maneuvers to qualify the pilots of the Puma helicopter of the Joint Helicopter Group (GIH) and two nautical raids conducted, day and night, by the marines from the gate of the raft.

As it approached the Toulon coast, the Tonnerre was towed by the Seine Metropolitan Support and Assistance Vessel (BSAM): an important mutual training, as it was little practiced by the PHA. The two crews took advantage of this opportunity to hone their know-how and increase their ability to maneuver together in all circumstances.