Full title reads: "Making Sure".
GV Depth charge exploding at sea - poor quality.
Shots of buoy being dropped to mark the point where the depth charge went off.
VS Good shots of French diver entering a deep sea diving suit and being lowered over the side and into the sea. He dived to ascertain whether a French ship had sunk a German U-boat several days earlier, and he found the wrecked submarine lying on the bottom of the sea.
He comes back to the surface and gets out of his suit.