to encounter bottom and he had lost his balance.
With great presence of mind, he kept the searchlight high in the air. He had stepped into a deep hole, and although he was up to his neck in water he kept his arm raised, keeping the flashlight free of the wetness.
"Here! Take the light," he gasped, in a hoarse whisper.
Joe leaned over and grasped the flashlight.
"Deep water here," muttered Frank, as he tried to scramble back into the shallows.
But the hole into which he had fallen was a sudden drop and it was necessary for Joe to grasp his brother's outstretched hand before he could regain the shallow water. At length, soaked to the skin, Frank again stood beside his brother.
"Good thing it wasn't any deeper," he remarked.
"The bottom is pretty level around here. It's funny there should be a deep hole like that."
Frank gave a sudden exclamation.
"I know how that came to be there," he whispered. "That's a channel! See how close it is to the shore. The water shouldn't be so deep right there."
"Why should it be a channel?"
"To let that motorboat get into shore—or
