On this day 11 July 1915

The German cruiser SMS KÖNIGSBERG, which had been hidden amongst the mangrove swamps deep in the Rufiji River delta in East Africa since September 1914, was finally destroyed by the 6-inch guns of the monitors HMS SEVERN and HMS MERSEY.

On 11 July 1915 the final attack began.  HMS Mersey and Severn, assisted by an Flt Lt Cull and Flt Sub Lt Arnold spotting in a Henry Farman F27, conducted a five-hour bombardment that destroyed the cruiser. The Farman was shot down, though the crew were recovered, and the spotting was taken over by Flt Lt H E M Watkins and Lt A G Bishop in the remaining Caudron which on return to base on Mafia Island made a bad landing, damaging the plane. The Konigsberg was sunk. Because there were no serviceable aircraft, no immediate reconnaissance of the Konigsberg took place.  On the 5th August its destruction was confirmed by Flt Lt V G Blackburn with Flt Lt Cull in the Observer's seat flying a Caudron GIII.

The part played by the men and machines of the RNAS had been vital, without them the monitors could have achieved little. The whole operation was a vindication of naval air power. For Konigsberg operations, Flt Lt John Tulloch Cull and Flt Sub-Lt Harwood James Arnold were awarded the DSO and Cull's Observer from the 25 April 1915 incident, Ldg Mech Ebeneezer Henry Alexander Boggis was awarded the DSM. (For full story see FAAOA heritage Timeline 11 July 1915)

Citation in London Gazette 7 December 1915

Flt Cdr Cull and Flt Sub Lt H.J. Arnold were spotting on 11 July, under fire, in a biplane, when the enemy's fire damaged it so that it descended in a quarter of an hour from 3200 feet to 2000 feet. During this time no attempt was made to return to the airstrip at Mafia, although it was obvious that this could not be done unless a start was made at once. Arnold continued to send his spotting signals the whole time, and when a quarter of an hour later the machine was again hit and forced to descend, Cull controlled the machine and Arnold continued to send spotting corrections to the last, after warning the Monitors that they were coming down, and would endeavour to land near them. The aeroplane finally came down in the river, turning over and over. Cull was nearly drowned, but was assisted by Arnold, and both were rescued by a boat from HMS Mersey.