War Nizam

I was reading about Arctic convoys when I remembered my Dad's picture of his ship in WW2. He was in the RFA in the North sea on a tanker. I was going to reframe it but then I realised it has a commendation on the back, from the Director of Royal Naval Trade Division.
Part of this reads The defensive equipment was used with effect, and the enemy attacks were successfully beaten off. The rapid and continuous fire from the whole of the ship's guns, and the effective use of the P.A.C.s caused the enemy to mistime his bombing. I am pleased to learn that there were no casualties and the personnel behaved with coolness during the action.
Dad didn't talk much about the war but now I wish he was still here, so I could ask him about it.