On 12 May 1918, HMS D6 (Lt C B Barry) was ordered to search for a German U-boat thought to be preparing to attack a troop convoy in the English Channel. Barry detected the U-boat and attacked from a range of 600 yards. The attack was successful and Lt Barry was awarded the DSO and, later, reached flag rank.

Two months later, on 24 June, under a new commanding officer (Lt S A Brooks), D6 was torpedoed and sunk off the Irish coast, by the German U-boat UB73 (Kapitanleutnant Neurether). There were no survivors.

Thus, D6 was the first submarine to sink and be sunk by another submarine.

By PJ: UB73 rescued 2 survivors, Lt Brooks and Bell. Check date‚ some say 24^th and some 28^th. Service record for one sailor says DD 29^th.