, ▁making ▁it ▁possible ▁that ▁M - 2 1 ▁attempted ▁to ▁attack ▁the ▁cru iser . ▁The ▁observer ▁ab o ard ▁Can ber ra ▁may ▁have ▁seen ▁b ub bles ▁from ▁the ▁com pressed ▁air ▁released ▁to ▁fire ▁the ▁tor ped o es . ▁ ▁Second ary ▁miss ions ▁As ▁per ▁the ▁operation ▁plan , ▁the ▁five ▁mother ▁sub mar ines ▁waited ▁off ▁Port ▁H ack ing ▁on ▁the ▁night s ▁of ▁ 1 ▁and ▁ 2 ▁June ▁for ▁the ▁m idget ▁sub mar ines ▁to ▁return . ▁FR U ME L ▁picked ▁up ▁wireless ▁traffic ▁between ▁the ▁five ▁sub mar ines , ▁leading ▁the ▁RA AF ▁to ▁task ▁three ▁Lock he ed ▁Hud s ons ▁and ▁two ▁Br istol ▁Beau fort s ▁with ▁finding ▁the ▁source ▁of ▁the ▁communic ations . ▁They ▁were ▁un success ful . ▁On ▁ 3 ▁June , ▁S as aki ▁abandoned ▁hope ▁of ▁recover ing ▁the ▁m idget ▁sub mar ines , ▁and ▁the ▁sub mar ines ▁dispers ed ▁on ▁their ▁secondary ▁miss ions . ▁ ▁Att acks ▁on ▁Al lied ▁merchant ▁sh ipping ▁Four ▁of ▁the ▁sub mar ines ▁began ▁operations ▁against ▁Al lied ▁merchant ▁sh ipping . ▁I - 2 1 ▁pat rolled ▁north ▁of ▁Sydney , ▁while ▁I - 2 4 ▁pat rolled ▁south ▁of ▁Sydney . ▁I - 2 7 ▁began ▁searching ▁off ▁Gab o ▁Island ▁for ▁ships ▁depart ing ▁Melbourne , ▁and ▁I - 2 9 ▁travel led ▁to ▁Br is b ane . ▁I - 2 2 ▁left ▁the ▁group ▁to