"She's gone under!" gasped Roger.
"Will she come up again?" asked Shadow, anxiously.
"There she is! Over there!" yelled Phil, and pointed to a spot several yards away.
A hand and an arm had shown themselves, but that was all. In less than two seconds they disappeared again.
Dave had done some rapid thinking. Before leaving the steamer the boys had thrown off their coats. Now standing up, Dave cast his cap to the bottom of the boat, and made a quick dive overboard.
"He's gone after her!"
"Good for Dave! It's the only thing to do if that girl is to be saved."
"Row on and keep your eyes wide open," directed Phil. "I don't think they'll get very far away."
Dave had calculated the distance as closely as possible, and once under water he pushed ahead with all speed in the direction where he had seen the hand and arm. While at Oak Hall he had learned the trick of swimming under water with his eyes open, and this now stood him in good stead.
"There she is," he thought, as he caught sight of something white passing just to the left of him. He made a quick turn, and a few seconds later had the girl by the hand. Then Dave caught her under the arms, and treading water, brought both her and himself to the surface.