[Brian]

Many thanks, Laurent

This is what the translated War Diary states:


13 July 1940 CONFIDENTIAL

The Groups will be advised accordingly.

English Channel :

FT boat flotillas off duty.

According to recent information one tanker of 15,000 tons (in
spite of her degaussing equipment) and another tanker of 6,000
tons were lost through striking mines (aerial) off St* Nazaire.
This shows that, despite all defense measures, aerial mines are
still effective and confirms the need of continuing to use them
as much as possible.

Presumably the "recent information" was incorrect!

Cheers
Brian