"That's right!" agreed Mr. Hardley. "We want to make a success of this trip."
He remained at the glass bull's-eyes, now and then exclaiming as some shad or other fair-sized fish came into view. Suddenly, however, his exclamation was sharper than usual.
"Look!" he exclaimed. "There's part of a wreck!"
Ned, Mr. Damon, and Tom looked out and saw, sweeping past them, the ribs and worm-eaten timbers of some craft, lying on the bottom of the river.
"Yes, that's the remains of an old brick scow," the young inventor explained. "That's one of our water-marks, so to speak. It is at the bend of the river. We turn now, and head for the bay."
As he spoke they all became aware of a sudden swerve in the course of the submarine. The helmsman had, doubtless, noted the "water-mark," as Tom termed it, and as an automobilist on land might swing at the cross-roads, the steersman was changing the course of his craft.
"We'll go deeper," said Tom a moment later, as the wreck passed out of view. "We can go about fifty feet down now. Yes, he's sinking her," he added, as a gauge showed the craft to be descending. "Nelson knows his business all right."
"He is your captain?" asked Mr. Hardley.
"One of the best, yes. He'll go with us on the search for the Pandora."
They talked of various matters, Tom relating to Mr. Hardley how a tug had rammed the brick scow some years ago, and sunk it in the river.