Hi,
I have been away, and not able to answer.
The FD.28 fits very good with the position of the located wreck (depth 100+ metres). No mines of FD.28 were reported nor swept, and nothing were found during the minesweeping by 56. M-Fl after the loss of the Huldra. It's strange that a minefield in the main sailingroute was undetected for more than a month, and only one mine remained at the self destruction date. Might indicate some error being made by the submarine during the laying?

I think that the most possible reason is the last mine of the FD.28 minefield, but a drifting mine can't be sorted out (the German conclusion was probably drifting mine.

Huldra was on voyage Ålesund - Thamshavn in ballast, and the crew was rescued by NM-16.

Best regards,
Erling