[Blacklight]

Okay had an unusual situation happen on my 3rd patrol in my type IIA.
Left kiel on my next patrol, not much sighted for about 4 days, I then get a hydrophone contact at long range and started to plot. Once the contact was identified (small freighter) and I was in a good firing position, I fired one eel at it set to magnetic, 1.5m under keel and got a direct hit. The vessel started to slow down and stopped dead after 12 minuest, then started to sink, BUT it got to within a few meters of sinking and stopped! Last I saw it was still there, and still refusing to sink.
Anyone else had this happen to them?
(I know I could of used a second eel, but I was conserving my supply of torpedoes)

The ship was carrying a much needed supply of cork to the battlefront.