"Do you see the big rollers coming ?" In truth the surface of the river was now beginning to behave in an unusual way.

Where, heretofore, the water had been choppy and whitecapped, the water now broke in longer, foam-crested waves.

Owing to the course of the wind the waves were rolling upstream.

Within five minutes from the time when Dave first called attention to the rougher water the waves had considerably increased in size.
"Oh, I'm glad I'm not out on the water," shivered Laura.
"So am I," Belle admitted candidly.
"Do you believe Tom Foss can bring his boat down against such waves!" Laura inquired.
"Oh, no doubt, he has had sense enough to run in somewhere and tie up," predicted Midshipman Dan charitably.
"I hope so," murmured Belle.

"But Tom is an awfully stubborn fellow." Toot! too-oo-oot! sounded a whistle up the river.
"By ginger, there comes Foss's boat now!" muttered Dan, standing up and staring.