ork ▁and ▁L imer ick , ▁and ▁another ▁special ist ▁unit , ▁the ▁Techn ical ▁Support ▁Unit . ▁As ▁of ▁May ▁ 2 0 1 8 ▁the ▁NS R ▁had ▁a ▁strength ▁of ▁ 1 1 5 ▁personnel ▁of ▁all ▁ranks . ▁The ▁reserve ▁supp lement s ▁the ▁crew ▁of ▁vessels ▁of ▁the ▁Irish ▁Naval ▁Service ▁during ▁pat rol s ▁of ▁territorial ▁waters ▁and ▁over se as ▁vis its , ▁as ▁well ▁as ▁conduct ing ▁stand - alone ▁operations ▁within ▁their ▁respective ▁ports , ▁such ▁as ▁security ▁duties , ▁sight ing ▁reports ▁and ▁intelligence ▁gather ing . ▁All ▁Naval ▁Service ▁Reserve ▁members ▁fall ▁under ▁the ▁Naval ▁Service ▁Executive ▁Division ▁( Se aman ' s ▁Division ). ▁ ▁En list ment ▁is ▁open ▁to ▁EU ▁citizens ▁between ▁the ▁ages ▁of ▁ 1 8 ▁and ▁ 3 5 , ▁provided ▁they ▁are ▁ordin arily ▁resident ▁in ▁Ireland , ▁can ▁pass ▁fit ness ▁tests , ▁an ▁interview , ▁medical ▁exam ination , ▁are ▁of ▁good ▁character ▁and ▁obtain ▁a ▁security ▁clear ance , ▁and ▁also ▁to ▁non - E U ▁citizens ▁who ▁have ▁been ▁continu ously ▁leg ally ▁resident ▁in ▁the ▁Republic ▁for ▁at ▁least ▁three ▁years . ▁ ▁The ▁NS R ▁is ▁a ▁part - time ▁volunt ary ▁organisation , ▁and ▁trains ▁members ▁in ▁aspects ▁of ▁na ut ical ▁and ▁military ▁discipl ines ▁to ▁supp lement ▁and ▁aid ▁the ▁permanent ▁Naval ▁Service . ▁Period s ▁of ▁en list ment ▁vary ▁and ▁is ▁initially ▁for ▁four ▁years . ▁Pro gression ▁through ▁the ▁ranks ▁is ▁possible ▁including