1 . ▁A ▁second ▁theory ▁was ▁that ▁the ▁m idget ▁attempted ▁to ▁return ▁to ▁the ▁mother ▁sub mar ines ▁but ▁exha usted ▁its ▁battery ▁power ▁before ▁reaching ▁the ▁Port ▁H ack ing ▁recovery ▁point ▁and ▁would ▁therefore ▁be ▁outside ▁and ▁to ▁the ▁south ▁of ▁Sydney ▁He ads . ▁The ▁third ▁theory ▁was ▁that ▁the ▁m idget ' s ▁crew ▁decided ▁to ▁avoid ▁end ang ering ▁the ▁five ▁larger ▁sub mar ines ▁during ▁the ▁recovery ▁process , ▁and ▁either ▁ran ▁straight ▁out ▁to ▁sea ▁or ▁head ed ▁north . ▁ ▁A ▁group ▁of ▁seven ▁amateur ▁sc uba ▁divers ▁solved ▁the ▁mystery ▁in ▁November ▁ 2 0 0 6 , ▁when ▁they ▁found ▁a ▁small ▁sub marine ▁sitting ▁u pr ight ▁on ▁the ▁se ab ed , ▁ ▁below ▁sea ▁level ▁and ▁approximately ▁ ▁from ▁B ung an ▁Head , ▁off ▁Sydney ' s ▁Northern ▁Be aches . ▁Commander ▁Sh ane ▁Moore , ▁the ▁officer ▁responsible ▁for ▁the ▁Royal ▁Australian ▁Navy ' s ▁her itage ▁collection , ▁confirmed ▁that ▁the ▁w reck ▁was ▁M - 2 4 ▁after ▁view ing ▁foot age ▁from ▁multiple ▁div es , ▁along ▁with ▁measurements ▁the ▁group ▁had ▁taken . ▁The ▁w reck ▁had ▁several ▁bullet ▁holes ▁in ▁it , ▁most ▁likely ▁from ▁Ch ic ag os ▁quad ru ple ▁machine - gun ▁mount . ▁The ▁location ▁of ▁the ▁w reck ▁was ▁kept ▁secret ▁by ▁both ▁the ▁divers ▁and ▁the ▁n avy , ▁with ▁Def ence ▁Minister ▁Br end an ▁Nelson ▁prom ising ▁to ▁have ▁the ▁w reck ▁protected ▁as