Shot in England of spotters looking skywards for enemy planes, antiaircraft guns searching sky. Interior shots of British aircraft plant. Shot of tanks being tested at full speed, smashing through water. Sequence on British warships being refuelled in port. Shots of survivors from sunken freighters being helped ashore from British warship at night. Sequence on sea battles, convoy. Shot of tankers being hit, exploding fiercely, much smoke. Shot of survivors being fished out of oily sea.