▁s inking ▁ 2 0 ▁merchant ▁ships ▁( 1 2 0 , 0 0 0 ▁tons ▁of ▁sh ipping ▁in ▁total ). ▁I - 3 0 ▁sa iled ▁around ▁the ▁Cape ▁of ▁Good ▁Hope ▁to ▁Lor ient , ▁arriv ing ▁there ▁on ▁August ▁ 5 ▁and ▁thereby ▁became ▁the ▁first ▁Japanese ▁sub marine ▁to ▁sail ▁into ▁German ▁territory ▁during ▁the ▁war . ▁On ▁October ▁ 1 3 ▁she ▁was ▁returning ▁from ▁Europe ▁to ▁Japan ▁when ▁she ▁struck ▁a ▁mine ▁and ▁s ank ▁ 3 ▁miles ▁east ▁of ▁Ke ppel ▁Har bour . ▁ ▁From ▁September ▁to ▁November ▁the ▁squad ron ' s ▁sub mar ines ▁s unk ▁another ▁ 2 2 4 , 5 0 0 ▁tons ▁of ▁sh ipping ▁( 4 0 ▁ships ▁in ▁total ) ▁in ▁the ▁Indian ▁Ocean . ▁ ▁In ▁November ▁the ▁two ▁auxili ary ▁cru is ers ▁associated ▁with ▁the ▁squad ron ' s ▁Mad agas car ▁operation ▁attacked ▁the ▁Dutch ▁tank er ▁O nd ina ▁and ▁her ▁Indian ▁esc ort ▁ship ▁the ▁H M IS ▁Beng al . ▁In ▁the ▁en su ing ▁battle ▁the ▁H ok oku ▁Mar u ▁was ▁destroyed ▁and ▁the ▁tank er ▁was ▁dam aged . ▁Both ▁the ▁A ik oku ▁Mar u ▁and ▁Beng al ▁were ▁und am aged ▁and ▁returned ▁to ▁their ▁respective ▁bases . ▁▁ 1 9 4 3 ▁ ▁In ▁ 1 9 4 3 ▁a ▁further ▁ 1 2 0 , 0 0 0 ▁tons ▁of ▁sh ipping ▁was ▁s unk ▁in ▁the ▁first ▁four ▁months ▁of ▁the