[1] When war was declared with Germany on 5 August 1914, E7 was based at Harwich, in the 8th Submarine Flotilla of the Home Fleets.

The U-boat′s commander, Oberleutnant zur See Heino von Heimburg, and UB-14's cook, a man by the name of Herzig, set out in a rowboat to observe the Ottoman attempts to destroy E7.

After several mines that formed part of the net had been detonated to no avail,[Note 1] von Heimburg and his group rowed out and repeatedly dropped a plumb line until it contacted metal.

[4] After the hand-dropped mine detonated too close for the British submarine's captain's comfort, he ordered his boat surfaced, abandoned, and scuttled.

Between shellfire from the Ottoman shore batteries and E7′s scuttling charges, von Heimburg and company narrowly escaped harm.