 In February 1942 the boat was ordered towards the Trondheim area along with HMS "Trident" to protect a convoy from enemy sorties from Norwegian ports.Although "Tuna" did not engage the enemy, "Trident" damaged the German cruiser "Prinz Eugen".On 30 November 1942, under the command of Lieutenant-Commander Dick Raikes DSO, "Tuna" sailed from Holy Loch, Scotland, inserting twelve Royal Marines swimmer canoeist commandos soon to become the SBS into the Gironde estuary as part of Operation Frankton (the attack on Bordeaux harbour).