oted ▁for ▁Brian ▁Miller , ▁the ▁husband ▁of ▁Elisabeth ▁S lad en , ▁although ▁her ▁withdraw al ▁from ▁the ▁project ▁meant ▁he ▁did ▁not ▁eventually ▁get ▁involved . ▁T oby ▁Asp in ▁as ▁Commander ▁Ste g , ▁the ▁leader ▁of ▁the ▁S ont aran ▁force ▁ch asing ▁the ▁R ut an . ▁Although ▁initially ▁ant agon istic ▁to ▁Lisa ▁Der anne ▁and ▁her ▁crew , ▁he ▁sacrific es ▁himself ▁to ▁destroy ▁the ▁R ut an ▁and ▁save ▁the ▁ship ▁at ▁the ▁story ' s ▁conclusion . ▁Asp in ▁would ▁later ▁appear ▁as ▁another ▁S ont aran ▁in ▁" M ind game ". ▁Tom ▁Finn is ▁as ▁Lieutenant ▁V orn , ▁Ste g ' s ▁second - in - command . ▁S light ly ▁dim w itted , ▁he ▁is ▁killed ▁by ▁the ▁R ut ans . ▁Finn is ▁would ▁later ▁appear ▁in ▁the ▁fan ▁production ▁The ▁F ew ▁Do ctors . ▁ ▁Production ▁The ▁film ▁was ▁shot ▁almost ▁entirely ▁on ▁location ▁ab o ard ▁the ▁Second ▁World ▁War - era ▁Royal ▁Navy ▁light ▁cru iser ▁, ▁perman ently ▁mo ored ▁at ▁Sym on ' s ▁Wh arf ▁on ▁the ▁River ▁Th ames ▁since ▁ 1 9 7 1 . ▁Some ▁scenes ▁were ▁also ▁shot ▁at ▁P ine wood ▁Studios . ▁Fil ming ▁ab o ard ▁the ▁vessel ▁was ▁frequently ▁pl ag ued ▁with ▁sound ▁problems ▁which ▁caused ▁the ▁film ▁crew ▁to ▁rapidly ▁fall ▁behind ▁schedule . ▁The ▁un lic ensed ▁nature ▁of ▁the ▁Dream watch ▁production ▁meant ▁that ▁they ▁could ▁not ▁even ▁refer