ed ▁Philadelphia ▁on ▁ 1 ▁May ▁ 1 9 6 6 , ▁reached ▁New ▁London ▁on ▁ 1 ▁June , ▁and ▁head ed ▁for ▁the ▁Car ib bean ▁for ▁int ensive ▁research . ▁Her ▁studies ▁during ▁ 1 9 6 6 ▁also ▁took ▁her ▁to ▁Nar rag ans ett ▁Bay ▁and ▁twice ▁to ▁B erm uda . ▁At ▁the ▁beginning ▁of ▁ 1 9 6 7 , ▁Gr ou per ▁was ▁at ▁New ▁London ▁prepar ing ▁to ▁res ume ▁gather ing ▁knowledge ▁of ▁under water ▁sound ▁propag ation . ▁ ▁Up ▁until ▁the ▁end ▁of ▁ 1 9 6 8 , ▁Gr ou per ▁was ▁still ▁adding ▁accomplish ments ▁as ▁a ▁floating ▁labor atory ▁to ▁her ▁long ▁and ▁out standing ▁record ▁during ▁both ▁war ▁and ▁peace . ▁▁ ▁In ▁May ▁ 1 9 6 5 ▁Gr ou per ▁sur pass ed ▁the ▁record ▁previously ▁held ▁by ▁O - 4 ▁for ▁serving ▁the ▁longest ▁as ▁the ▁oldest ▁sub marine ▁in ▁the ▁US ▁Navy . ▁ ▁She ▁was ▁the ▁oldest ▁US ▁Navy ▁sub marine ▁in ▁service ▁from ▁December ▁ 1 9 4 6 ▁until ▁her ▁de comm ission ing , ▁a ▁total ▁of ▁ 2 2 ▁years . ▁ ▁She ▁was ▁de comm ission ed ▁and ▁str icken ▁on ▁December ▁ 2 , ▁ 1 9 6 8 . ▁ ▁On ▁August ▁ 1 1 , ▁ 1 9 7 0 , ▁Gr ou per '' ▁was ▁sold ▁for ▁scra pping . ▁ ▁Awards ▁Navy ▁E ▁Rib bon ▁American ▁Camp aign ▁Medal ▁A si atic