"But we don't want you to drown us, and this boat has a bad habit of not keeping on the top of the water."

"She will keep on the top of the water most of the time, and the worst you have to fear is a wet jacket."

Just as the schooner was going in under the lee of Garden Island, another wave broke against her side, and about half a barrel of water dropped into the standing-room.

"There it is again!" exclaimed Thad.

"That's all right," added Dory. "No boat can keep all the water on the outside of her in such a sea as this. But she is working beautifully. Do you see that rope, Thad?" continued the skipper, pointing to the line by which the centre-board was handled.

"I see it, but I haven't the least idea what it is for."

"I want you and Nat to haul up the centre-board, for we don't need quite so much of it while we are going free."

The two boys named cast off the line, and pulled with all their might; but they could not start the board, as Dory did not suppose they could while the whole force of the wind was acting against it. The two hands at the line did not know what the centre-board was, or where it was; but the skipper thought, as they seemed to be a little concerned about their safety, that it was better for them to be employed.

"It's no use!" cried Thad. "I don't know what we are pulling at; but, whatever it is, it won't come."

"What is there down there?" asked Nat Long, looking into the pump, which was at the end of the centre-board casing.