0 2 : 3 0 ▁on ▁ 8 ▁June , ▁two ▁of ▁the ▁sub mar ines ▁bomb arded ▁the ▁ports ▁of ▁Sydney ▁and ▁New castle . ▁ ▁The ▁m idget ▁sub marine ▁attacks ▁and ▁subsequent ▁bomb ard ments ▁are ▁among ▁the ▁best - known ▁examples ▁of ▁A xis ▁naval ▁activity ▁in ▁Australian ▁waters ▁during ▁World ▁War ▁II , ▁and ▁are ▁the ▁only ▁occasion ▁in ▁history ▁when ▁either ▁city ▁has ▁come ▁under ▁attack . ▁The ▁physical ▁effects ▁were ▁slight : ▁the ▁Japanese ▁had ▁intended ▁to ▁destroy ▁several ▁major ▁war ships , ▁but ▁s ank ▁only ▁an ▁un ar med ▁dep ot ▁ship ▁and ▁failed ▁to ▁damage ▁any ▁significant ▁targets ▁during ▁the ▁bomb ard ments . ▁The ▁main ▁impact ▁was ▁psych ological ; ▁creating ▁popular ▁fear ▁of ▁an ▁imp ending ▁Japanese ▁invasion ▁and ▁forcing ▁the ▁Australian ▁military ▁to ▁upgrade ▁def ences , ▁including ▁the ▁comm enc ement ▁of ▁con voy ▁operations ▁to ▁protect ▁merchant ▁sh ipping . ▁ ▁Forces ▁ ▁Japanese ▁The ▁Imperial ▁Japanese ▁Navy ▁originally ▁intended ▁to ▁use ▁six ▁sub mar ines ▁in ▁the ▁attack ▁on ▁Sydney ▁Har bour : ▁B 1 - type ▁sub mar ines ▁, ▁, ▁, ▁and ▁, ▁and ▁C 1 - type ▁sub mar ines ▁ ▁and ▁. ▁The ▁six ▁sub mar ines ▁made ▁up ▁the ▁Eastern ▁Att ack ▁Group ▁of ▁the ▁ 8 th ▁Sub marine ▁Squadron , ▁under ▁the ▁command ▁of ▁Captain ▁H ank y u ▁S as aki . ▁ ▁On ▁ 8 ▁June ▁ 1 9 4 2 , ▁I - 2 1 ▁and ▁I