▁boat ▁was ▁commission ed ▁on ▁ 1 ▁May ▁ 1 9 4 1 ▁with ▁Lieutenant ▁Commander ▁Allen ▁R . ▁Joy ce ▁in ▁command . ▁ ▁Pre - World ▁War ▁II ▁service ▁ ▁On ▁ 2 0 ▁June ▁ 1 9 4 1 ▁Gren ad ier ▁participated ▁in ▁the ▁search ▁for ▁, ▁which ▁had ▁failed ▁to ▁surface ▁after ▁a ▁deep ▁test ▁d ive , ▁and ▁was ▁present ▁two ▁days ▁later ▁as ▁mem orial ▁exer cis es ▁were ▁conducted ▁over ▁the ▁spot ▁where ▁O - 9 ▁and ▁her ▁crew ▁lay . ▁After ▁sh aked own ▁in ▁the ▁Car ib bean ▁Sea , ▁Gren ad ier ▁returned ▁to ▁Port sm outh ▁on ▁ 5 ▁November ▁for ▁ref it . ▁Less ▁than ▁three ▁weeks ▁after ▁the ▁Japanese ▁attack ▁on ▁Pear l ▁Har bor , ▁she ▁sa iled ▁for ▁the ▁Pacific ▁to ▁join ▁the ▁sub marine ▁fleet . ▁ ▁CO MS UB P AC ▁pat rol s , ▁ 1 9 4 2 ▁ ▁Gren ad iers ▁first ▁war ▁pat rol ▁from ▁ 4 ▁February ▁to ▁ 2 3 ▁March ▁ 1 9 4 2 ▁took ▁her ▁near ▁the ▁Japanese ▁home ▁islands , ▁off ▁the ▁coast ▁of ▁H ons h ū , ▁and ▁brought ▁her ▁several ▁targets ▁but ▁no ▁sink ings . ▁On ▁ 1 2 ▁April ▁Gren ad ier , ▁now ▁under ▁command ▁of ▁L CD R ▁Will is ▁L ent , ▁depart ed ▁Pear l ▁Har bor ▁for ▁her ▁second ▁war ▁pat rol , ▁along ▁the ▁Shang hai - Y ok oh ama ▁and ▁Nag as