Speaking of swimming, that was an art in which several of the boys, as well as Bessie Lavine and Mina Everett, needed practice. Beside the early morning dip, both clubs often held swimming matches either at Green Knoll Camp, or off the boys' camp on Gannet Island. The boys built a good diving raft and anchored it in deep water after much hard work. The good swimmers among the girls--especially Wyn and Grace--liked to paddle over to the raft and dive from it. Late in the afternoon the Go-Aheads had come to the raft in their canoes dressed only in their bathing suits, and found that the boys had gone off on some excursion, and that even Professor Skillings was not in sight at Cave-in-the-Wood Camp. "Oh, goody!" exclaimed Bess, with satisfaction. "Now we can have a good time without those trifling boys bothering us. I'm going to learn to dive properly, Wyn." "Sure," returned her friend and captain, encouragingly. "Now's the time," and she gave Bess a good deal of attention for some few minutes. The other girls disported themselves in the deep water to their vast enjoyment. Bessie learned a good bit about diving and finally sat upon the edge of the float to rest. Wyn dived overboard. She had taken a long slant out from the float, but once under the surface she turned and went deeper. She was like an otter in the water, and having stuffed her ears with cotton she felt prepared to remain below a long time. Once she had opened her eyes while diving with Bess, and she thought she saw a shadowy something on the bottom of the lake that was neither a boulder nor a waterlogged snag. She beat her way to the bottom as rapidly as possible; but the light did not follow her. She could see nothing when she opened her eyes. It seemed as though something overshadowed her. The water was tugging at her; she could not remain below for long. But as she turned to drift up again, her shoulder touched something. She struck out and reached it. But the blow really pushed her away and she floated upward toward the surface. When she paddled to the raft she was panting, and Frank demanded: "What's the matter, Wyn? You look as if you'd seen a ghost I believe you stay down too long." "No," gasped Wyn. "I--I hit something." "What was it?" "Why--why, it looked like a wagon. 'Twas something." "I suppose so!" laughed Frank. "Wagon with a load of hay on it--eh?" Wyn said nothing more. She sat upon the float, with her knees drawn up and hugged in her brown arms, and thought. The other girls could get nothing out of her. She wasn't dreaming, however. She was thinking to a serious purpose. It _had_ looked like a wagon--as much as it looked like anything else. But, of course, she had seen it very dimly. She knew by the touch that it was of wood; but it was no waterlogged tree, although there was slime upon it It was not rough; but smooth.