"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.