▁World ▁War ▁II , ▁the ▁Royal ▁Navy ▁had ▁a ▁major ▁base ▁there , ▁en abling ▁them ▁to ▁challenge ▁any ▁attempt ▁by ▁German ▁war ships ▁to ▁emer ge ▁into ▁the ▁ocean ▁through ▁the ▁Norwegian ▁Sea . ▁After ▁the ▁Arm ist ice ▁in ▁ 1 9 1 8 , ▁the ▁German ▁High ▁Se as ▁Fle et ▁was ▁transferred ▁in ▁its ▁entire ty ▁to ▁Sc apa ▁Flow ▁while ▁a ▁decision ▁was ▁to ▁be ▁made ▁on ▁its ▁future ; ▁however , ▁the ▁German ▁sail ors ▁opened ▁their ▁sea - co cks ▁and ▁sc utt led ▁all ▁the ▁ships . ▁Most ▁ships ▁were ▁salv aged , ▁but ▁the ▁remaining ▁w re cks ▁are ▁now ▁a ▁fav oured ▁ha unt ▁of ▁recre ational ▁divers . ▁ ▁Second ▁World ▁War ▁ ▁One ▁month ▁into ▁World ▁War ▁II , ▁the ▁Royal ▁Navy ▁batt les hip ▁HMS ▁Royal ▁Oak ▁was ▁s unk ▁by ▁a ▁German ▁U - bo at ▁in ▁Sc apa ▁Flow . ▁ ▁As ▁a ▁result , ▁bar riers ▁were ▁built ▁to ▁close ▁most ▁of ▁the ▁access ▁channels ; ▁these ▁had ▁the ▁additional ▁advantage ▁of ▁creating ▁cause ways ▁where by ▁trav ellers ▁can ▁go ▁from ▁island ▁to ▁island ▁by ▁road ▁instead ▁of ▁being ▁obliged ▁to ▁rely ▁on ▁boats . ▁ ▁In ▁the ▁course ▁of ▁the ▁Second ▁World ▁War ▁Italian ▁prisoners ▁of ▁war ▁were ▁kept ▁on ▁Or k ney ▁Main land ; ▁they ▁impro vised ▁a ▁chap el ▁with ▁elaborate ▁architecture ▁out ▁of ▁cor rug ated ▁iron ▁and ▁other ▁base ▁materials , ▁which ▁is ▁now ▁a ▁tour ist ▁att raction .