id down, and he hung by one arm,
waist-deep in the water.

OO-OO-OO-OOH!!!

From the inverted mouth of the whistle, a few feet above, a hoarse,
deafening blast roared down into his face.

As he flung up his right hand and passed the end of the painter through
the lug a body shot over his head. Spurling had leaped on the top of the
dropping buoy. Percy was dragged down under the surface, the whistle
still ringing in his ears. He clung desperately to lug and painter.

The vibrations ceased. The can had reached its lowest point. It was
rising again. Out came his head.

"Can you hold on a minute, Perce?" roared Spurling's voice.

"Yes," strangled Percy.

"Then let go that painter! I've got it."

Hanging head down, his legs twined round a bail, Spurling worked rapidly
with both hands. Soon he had fastened the rope securely to the lug,
mooring the dory to the buoy.

OO-OO-OO-OOH!

The can was sinking again. Putting both hands under Percy's arms, Jim
lifted him. Then he lowered his grip to the boy's waist. That terrific
blast rendered speech inaudible, but Percy understood. As the water
raised part of his weight, he scrambled up over his friend's body.

Thirty seconds later, drenched and gasping, they stood clinging to the
bails on the top of the buoy.

XIX

ON THE WHISTLER

Jim was the first to recover his breath.

"Well!" he ejaculated. "Here we are! And mighty fortunate! We'll neither
of us ever have a closer shave."

He looked southwest, where the ledge was breaking white through the
gloom, and shook his head. Percy, shivering with excitement, said
nothing; but he felt as thankful as his mate. They stood close together
on the circular top, holding on to the crossed bails, waist-high.
Between them rose the whistle, thirty inches tall. Every time they sank
in the trough it emitted its dismal bellow.

To leeward the dory wallowed at the end of her painter, almost full of
water.

"Split her bow when we struck," said Spurling. "Just as well not to be
in her. At any rate, we're not drifting."

Their position, however, was none too secure. The buoy had a rise and
fall of seven feet. Unsteadied by keel or rudder, it bobbed unexpectedly
this way and that. The boys were obliged to cling fast to keep their
footing on the narrow, slippery top.

A sudden jump of the rolling can wrenched Percy's right hand from its
hold. But for his left, he would have been flung into the sea.

"That won't do," said