termined to risk minor dangers by turning in more
toward the shore. If he could only listen for the beating of the
rollers on the beach, it would be possible to tell when they came to
the open bay by the sudden cessation of this sound.

"What are you changing the course for?" demanded George, suspiciously,
a minute later, though he followed suit readily enough, determined not
to get far away from the other more stable boats.

"We'd better get in nearer shore, so we can hear the sound of the
surf," Jack replied.

"Oh! I see, you hope to keep tabs on our course by ear, when the eye
fails us; is that it, Jack?" asked Herb.

"That's one reason," Jack called back. "Perhaps we may be able to tell
when we're opposite the mouth of the bay, if we listen carefully. But
in another five minutes that fog will be down on us, boys, by the way
it creeps on, faster than we are going."

"How about signals?" asked George.

"Every boat has a horn of some sort, and you remember what the
different blasts mean. The _Tramp_ is a single toot, the _Comfort_ two
in quick succession, while your _Wireless_ is denoted by three sharp
ones, George. Four will mean that we must turn a little more to
starboard, and five, draw closer together for a confab. Got all that,
now?"

"All right here, Jack," assented Herb.

"And ditto with us," declared George.

"Well, be watchful and ready for anything, for here comes the wet
blanket to cover us," observed Jack.

It was a nasty fog, as thick as pea soup, as George called out a little
later. First the outlines of the shore were blotted out as though by
an impenetrable curtain. Then even the boats, close as they were,
began to go, until it was no longer possible to distinguish them from
the sea of gray vapor around.

Naturally the boys felt exceedingly nervous every minute of the time.
Jack had reduced speed, for he did not wish to run past the mouth of
Winyah Bay, if such a thing could be prevented by due caution.

An hour crept along. It seemed like three times that length of time to
every one of the listening lads. All this while they had managed to
catch that low throbbing sound from the shore. Sometimes it would be
very faint, and require careful work in order to locate it; then again
the beat of the waves on the sandy strand came quite distinctly.

Somehow, as long as they could catch this reassuring sound, they seemed
to feel renewed confidence. And yet the strain was terrible.