I was browsing around on the Royal Navy Submarine Museum in Gosport's web site. There is a page
giving a short description of british sub losses from 1904 to the present. Regarding th Sterlet
the following text can be found.
18 April 1940
Sunk in Skagerrak by German escort Vessel M75
On 8th April 1940 HMS Sterlet
left for a patrol in the Skagerrak, Norway. Four days later she signalled that she had unsuccessfully attacked a Convoy of 3 Merchant ships and a Destroyer. The following day she was assigned a new patrol area and on the 18th torpedoed the German Gunnery Ship Brummer
, causing serious damage. At once the German escorts counter attacked with repeated depth charge attacks. Their target never resurfaced.
There seeem to be some kind of mixup here. The Brummer
was sunk on 14.4.40. If the Sterlet
was sunk in the counterattack she can't have been lost on 18.4.40. What gives?