"Let's go down stream.

Spread out, and every now and then bob under and take as near a look at the bottom as you can." "It doesn't look right," Dave admitted as they all started back.
Several times they went under water, the best swimmers among them getting close to bottom.

So they continued on down the stream for some distance.
"Now, all together.

Go under water all at the same time," ordered Dick.
Below the surface of the river they went.

One after another their heads presently appeared above the surface once more.
"Have you fellows lost anything ?" quizzed Reade, suddenly appearing on the bank.
"That's what I call a mean trick on us!" cried Dave, flushing slightly.
"You fellows were in for a swim, weren't you ?" Reade drawled.
"You have been having it." With that he took to the water himself.