Well,

we might took into consideration that UB 72 was in that area and was lost on 12.05.1918 in the Channel by torpedoes fired by the british sub D 4.

That she's responsible I nethertheless find not very likely because there were 3 survivors from UB 72's sinking and they gave no information in that regard during interrogation.

On the other hand, their information was not very accurate at all, so ....

Oliver