, ▁Gr ou per ▁emer ged ▁from ▁the ▁yard ▁on ▁ 2 7 ▁June ▁ 1 9 5 1 ▁to ▁pione er ▁in ▁research ▁on ▁the ▁dead ly ▁sub marine - vers us - sub marine ▁war fare . ▁For ▁the ▁next ▁eight ▁years , ▁as ▁a ▁unit ▁of ▁Sub marine ▁Development ▁Group ▁ 2 , ▁Gr ou per ▁worked ▁to ▁develop ▁and ▁test ▁concepts ▁of ▁h unter - k iller ▁ant is ub marine ▁war fare . ▁In ▁this ▁duty , ▁she ▁r anged ▁along ▁the ▁East ▁Coast ▁from ▁Nova ▁Scot ia ▁to ▁Florida , ▁as ▁well ▁as ▁particip ating ▁in ▁Car ib bean ▁exer cis es . ▁In ▁ 1 9 5 3 ▁and ▁ 1 9 5 5 , ▁exer cis es ▁took ▁Gr ou per ▁across ▁the ▁Atlantic ▁to ▁Roth es ay , ▁via ▁I cel and . ▁In ▁the ▁fall ▁of ▁ 1 9 5 7 , ▁she ▁then ▁participated ▁in ▁NAT O ▁man eu vers . ▁▁▁ 1 9 5 8 ▁– ▁ 1 9 6 2 ▁▁ ▁Gr ou per ▁was ▁rec lass ified ▁AG SS - 2 1 4 '' ', ▁ 1 7 ▁May ▁ 1 9 5 8 , ▁and ▁on ▁ 2 8 ▁November ▁ 1 9 5 9 ▁she ▁entered ▁the ▁Port sm outh ▁Navy ▁Y ard ▁for ▁extensive ▁modification . ▁Her ▁forward ▁tor ped o ▁room ▁was ▁converted ▁into ▁a ▁floating ▁labor atory ; ▁work ▁ben ches ▁and ▁additional ▁ber th s ▁for ▁scient ists ▁were ▁installed , ▁and ▁various