▁the ▁Mediter rane an ▁tradition ally ▁as cribed ▁to ▁the ▁Arab ▁expansion ▁of ▁the ▁early - 7 th ▁century . ▁This ▁was ▁due ▁mainly ▁to ▁the ▁earliest ▁( at ▁that ▁time ) ▁icon ographic ▁dep ict ions ▁of ▁late en ▁rig ged ▁ships ▁from ▁the ▁Mediter rane an ▁post - dating ▁the ▁Islam ic ▁expansion ▁into ▁the ▁Mediter rane an ▁bas in ... It ▁was ▁assumed ▁that ▁the ▁Arab ▁people ▁who ▁inv aded ▁the ▁Mediter rane an ▁bas in ▁in ▁the ▁ 7 th ▁century ▁carried ▁with ▁them ▁the ▁sail ing ▁rig ▁familiar ▁to ▁them . ▁Such ▁theories ▁have ▁been ▁su pers eded ▁by ▁une qu iv ocal ▁dep ict ions ▁of ▁late en - rig ged ▁Mediter rane an ▁sail ing ▁vessels ▁which ▁pre - date ▁the ▁Arab ▁invasion . To ▁the ▁same ▁effect : ▁; ▁; ▁▁ ▁Further ▁in qui ries ▁into ▁the ▁appearance ▁of ▁the ▁late en ▁rig ▁in ▁the ▁Indian ▁Ocean ▁and ▁its ▁g ul fs ▁show ▁a ▁revers al ▁of ▁earlier ▁scholar ly ▁opinion ▁on ▁the ▁direction ▁of ▁diffusion , ▁now ▁pointing ▁to ▁an ▁introduction ▁by ▁Portuguese ▁sail ors ▁in ▁the ▁w ake ▁of ▁Vas co ▁da ▁G ama ' s ▁arrival ▁in ▁India ▁in ▁ 1 5 0 0 . ▁Search es ▁for ▁late en ▁s ails ▁in ▁India ▁were ▁incon clus ive . ▁Since ▁late en ▁s ails ▁were ▁absent ▁from ▁Indian ▁in land ▁waters , ▁that ▁is ▁in ▁regions ▁remote ▁from ▁foreign ▁influ ences , ▁as ▁late ▁as ▁the ▁mid - 2 0 th ▁century