From the Admiralty War Diary for 20 June 1941:
https://cd.royalnavy.mod.uk/-/media/...bd09e960a227cc
"Enemy Air Operations …HMT CAPSTONE destroyed an enemy plane which attacked her at 0419/20 in approx. 50º 6' N 5º 32' W …
Enemy Air Operations (contd.) … 0419/20 in 50º 6' 6" 5º 32' 6" W. No survivors. (F.O.I.C. Falmouth 1330/20)"