“See that canoe over there,” broke in Pepper, and pointing to another boat.  “They will be in trouble pretty soon if they don’t watch out.”

“Where away?” asked Rand.

“Over there by the other shore,” replied Pepper.  “They will turn turtle sure, if that wave catches them sideways.”

The boys were resting on their oars, watching the rapidly-approaching boat.

“Maybe we had better row over that way,” suggested Donald.  “There are a couple of girls in the canoe and they may need some help.”

“That chap is all right,” concluded Rand, after he had watched the canoe for a little while.  “He knows how to handle it.  He is doing fine.  See, he is just touching the water with his paddle, so as to keep it head-on.  Maybe he thinks we will need some help.”

Nevertheless, the boys kept on a course that would bring them near enough to the canoe to aid its occupants if they should need it.

“Now look at that!” cried Donald suddenly, when the boys were a hundred yards from the canoe.  “Did you ever see such a fool trick as that?  Just when he was coming out all right, too.  Pull for ail you are worth, boys!”

Even as he spoke the boys had gripped their oars and sent their boat at racing speed for the canoe.

What had called forth Donald’s exclamation was, that just as the Dart was passing the canoe one of the girls, who was seated in the stern, had suddenly risen to her feet to wave her handkerchief at some one on the yacht.  As she stood up the swell from the yacht caught the light craft, rolling it from side to side, and the girl losing her balance pitched headlong over the side of the boat, capsizing it.  In a moment they were all struggling in the river.  As the canoe went over the man caught the girl nearest to him and helped her to the boat and then turned to aid the other girl, but she had disappeared.

“Nellie!” he called, striking out in the direction he had last seen her.  “Nellie, Nellie! where are you?”

By this time the boys had reached the scene of the upset.

“Keep up your courage,” shouted Rand, “we’ll pick you up!”

[Illustration:  “They were all struggling in the water.”]

“Never mind me!” called the young man as they came near.  “See if you can’t save my sister.  She doesn’t know how to swim.”

“All right,” called Rand, “we’ll find her.”

“Where has she gone?” asked Donald.

“I don’t see anything of her,” said Rand, who was standing in the bow of the boat intently watching for any sign of the girl.  “Yes, there she is.”  A pale face had appeared for a moment on the surface.  “Straight ahead, boys!”

As the boat came to the spot where he had seen her Rand made a long dive overboard, coming up a moment later with the inanimate body of the girl.  He was joined almost immediately by Donald, who had followed him overboard, and so aided him in supporting her until Pepper and Jack had reached them with the boat.