South Africa sailors patrol their shores for illegal cargo vessels and mines.
Full title reads: "Contraband Control At The Cape".
VS coastguards sighting and halting an American merchant ship just off the South African coast. They signal the ship to stop, with flags and aldis lamp signals.
VS of coast guard cutter going alongside the merchant ship and of the officials checking the ship's papers.
MSs of coastal gun battery with the gun trained on the merchant ship which is lying just off shore.
MS Men pushing depth charge off the stern of the minesweeper.
GV of depth charge exploding behind ship with naval ensign flying to left of frame.