Then the young chief engineer began to experiment with the searchlight.
"What's the idea, sir ?" asked Conlon, looking on.
"I want to depress the light, so that we can use it to look down into the water." "And try to find the bombs ?" "Exactly," Reade nodded.
"Lucky if we don't find the bombs with the keel of the boat," observed Conlon.
Tom succeeded in rigging the light so that he could use it.

By the time that the boat was around at the west side of the retaining wall Tom ordered the boat in close alongside.

Then, with the depressed searchlight he discovered that he could see the sides of the wall to a depth of some eight feet under the surface.
"That may be enough for our needs," Reade murmured.

"Now, run the boat along, slowly and close.

I want to scan every bit of the wall." Less than five minutes later Tom Reade, one hand controlling the searchlight and peering steadily into the water, sang out: "Stop! Back her---slowly.