. ▁The ▁m idget ▁sub marine ▁intended ▁for ▁I - 2 8 ▁replaced ▁the ▁dam aged ▁m idget . ▁ ▁Al lies ▁ ▁The ▁naval ▁officer - in - charge ▁of ▁Sydney ▁Har bour ▁at ▁the ▁time ▁of ▁the ▁attack ▁was ▁R ear ▁Admir al ▁Ger ard ▁Mu ir head - G ould ▁of ▁the ▁Royal ▁Navy . ▁On ▁the ▁night ▁of ▁the ▁attack , ▁three ▁major ▁vessels ▁were ▁present ▁in ▁Sydney ▁Har bour ; ▁the ▁heavy ▁cru is ers ▁ ▁and ▁, ▁and ▁the ▁light ▁cru iser ▁. ▁Other ▁war ships ▁in ▁the ▁har bour ▁included : ▁destroy er ▁tender ▁, ▁auxili ary ▁min el ayer ▁, ▁cor v ettes ▁, ▁, ▁and ▁, ▁armed ▁merchant ▁cru is ers ▁ ▁and ▁, ▁and ▁Dutch ▁sub marine ▁K - IX . ▁A ▁converted ▁fer ry — H MA S ▁K ut tab ul — was ▁alongside ▁at ▁Garden ▁Island ▁where ▁she ▁served ▁as ▁a ▁temporary ▁bar ra cks ▁for ▁sail ors ▁transfer ring ▁between ▁ships . ▁The ▁hospital ▁ship ▁O ran je ▁had ▁also ▁been ▁in ▁the ▁har bour , ▁but ▁depart ed ▁an ▁hour ▁before ▁the ▁attack . ▁ ▁Har bour ▁def ences ▁At ▁the ▁time ▁of ▁the ▁attack , ▁the ▁static ▁Sydney ▁Har bour ▁def ences ▁consisted ▁of ▁eight ▁anti - sub marine ▁indicator ▁loops   – ▁six ▁outside ▁the ▁har bour , ▁one ▁between ▁North ▁Head ▁and ▁South ▁Head , ▁and ▁one ▁between ▁South ▁Head ▁and ▁Middle ▁Head , ▁as ▁well ▁as ▁the ▁partially ▁constructed ▁Sydney ▁Har bour ▁anti -