HMS THAMES (Lt Cdr W D Dunkerley) was patrolling off Norway when it is almost certain that she encountered the German Battle cruiser Gneisenau and her escorts. At 1550 on the afternoon of 26 July, one of the escorts, Luchs, was torpedoed and sank within 30 seconds. THAMES was the only feasible candidate for the attack and may herself have been damaged in the incident if her torpedo had exploded prematurely.

If this was not the cause of her loss, then she was probably mined in one of several minefields that she would have had to negotiate en route to her home port. There were no survivors.