0 ▁r ounds ▁from ▁her ▁ 2 0 mm ▁anti - air craft ▁weapon ▁and ▁ 4 0 0 ▁r ounds ▁from ▁her ▁M G ▁ 3 4 ▁machine ▁gun ▁at ▁the ▁merchant man . ▁ ▁The ▁boat ▁returned ▁to ▁France , ▁to ▁St . ▁Naz aire ▁on ▁ 8 ▁July . ▁ ▁Unfortunately ▁for ▁the ▁crew ▁of ▁U - 6 9 , ▁it ▁was ▁nearly ▁a ▁year ▁before ▁they ▁s ank ▁another ▁ship , ▁due ▁to ▁the ▁tight ening ▁of ▁con vo ys ▁in ▁the ▁second ▁half ▁of ▁ 1 9 4 1 ▁and ▁some ▁fr ustr ating ly ▁short ▁pat rol s , ▁called ▁off ▁because ▁of ▁mechanical ▁failure ▁or ▁sick ness ▁on ▁the ▁boat . ▁▁ 4 th ▁and ▁ 5 th ▁pat rol s ▁Pat rol ▁number ▁four ▁was ▁relatively ▁short , ▁last ing ▁bare ly ▁a ▁week ▁and ▁hardly ▁leaving ▁the ▁Bay ▁of ▁B isc ay . ▁ ▁U - 6 9 s ▁fifth ▁pat rol ▁took ▁her ▁north west ▁of ▁St . ▁Naz aire ▁towards ▁Green land ; ▁although ▁longer , ▁it ▁was ▁also ▁un success ful . ▁▁ 6 th ▁and ▁ 7 th ▁pat rol s ▁The ▁boat ' s ▁sixth ▁pat rol ▁was ▁une vent ful . ▁ ▁During ▁her ▁sevent h ▁out ing , ▁she ▁was ▁depth ▁charged ▁for ▁several ▁hours ▁by ▁esc ort s ▁of ▁a ▁con voy ▁on ▁ 2 1 ▁March , ▁west ▁of ▁Ireland . ▁She ▁escaped ▁without ▁any ▁damage . ▁▁ 8 th ▁pat rol ▁U - 6