▁however , ▁the ▁situation ▁changed ▁– ▁R ear - Ad mir al ▁Jean ▁Lac ros se ▁at ▁Cher bourg ▁had ▁been ▁informed ▁of ▁Mus ke in ' s ▁difficulties ▁and ▁sent ▁rein for c ements ▁of ▁ 4 0   b arg es ▁and ▁armed ▁fish ing ▁ships ▁to ▁S allen elles . ▁ ▁Late ▁in ▁April , ▁Mus ke in ▁had ▁an ▁opportunity ▁to ▁escape ▁without ▁inter ception ▁by ▁the ▁British ▁force ▁off sh ore ▁and ▁sa iled ▁as ▁far ▁as ▁Saint - V a ast - la - H oug ue , ▁to ▁the ▁west ▁of ▁the ▁islands . ▁There ▁he ▁waited ▁for ▁the ▁right ▁combination ▁of ▁wind ▁and ▁t ide ▁to ▁allow ▁the ▁attack ▁to ▁go ▁ahead ▁un inter rupted ▁by ▁the ▁British ▁squad ron ▁that ▁had ▁followed ▁his ▁fl ot illa ▁west wards . ▁ ▁Battle ▁On ▁ 6 ▁May ▁the ▁conditions ▁for ▁Mus ke in ' s ▁attack ▁were ▁perfect : ▁the ▁calm ▁wind s ▁prevent ed ▁the ▁British ▁war ships ▁intercept ing ▁his ▁fl ot illa , ▁and ▁the ▁weak ▁t ides ▁prevent ed ▁dis ruption ▁of ▁his ▁craft ▁by ▁heavy ▁waves . ▁The ▁British ▁also ▁were ▁aware ▁of ▁the ▁conditions ▁necessary ▁for ▁the ▁attack , ▁and ▁made ▁swift ▁prepar ations ▁to ▁arm ▁the ▁batter ies ▁and ▁line ▁the ▁shore ▁with ▁Royal ▁Mar ines . ▁A ▁small ▁boat ▁from ▁the ▁islands ▁watched ▁as ▁Mus ke in ' s ▁force ▁row ed ▁out ▁of ▁Saint - V a ast - la - H oug ue ▁and ▁stead ily