“What is it?” asked Jack with keen interest.

“I believe it is a warship of some sort!” replied Ned.

“Then they’ll capture us and take us to port mighty quick!”

“I guess they’ll capture us all right!” put in Frank. “I can see the sailing vessel making signals. They’ve got a string of flags flying from the foretopmast head. I don’t know what they mean, but they’re calls for help, or I’ll miss my guess! They are something like the U. S. flags!”

Those on board the steamer had evidently seen the string of flags or else by the peculiar actions of the sailing vessel guessed that something was wrong, for the boys saw that their course was at once altered. From the clouds of dense black smoke pouring from the funnels they knew that the stokers were being urged to their best efforts.

In a short space of time the combined speeds of the two vessels brought them close together. As the other approached, Harry shut off the power of the engines, checking them to little more than steerageway.

As the steamer passed the ship Ned could see that some communication had been made between the two. The steamer came quickly on.

“Pass me up that white flag again, Harry,” requested Ned. “I think they’re coming up to speak to us, and I’d just as soon have that handy. Maybe these fellows might misunderstand our motives, too!”

“I wish now I hadn’t painted that ‘U-13’ quite so plainly on the sides!” grumbled Jimmie. “I’ll bet they’ve seen that!”

“Of course, they’ve seen it, but if we show a white flag they won’t do anything to us. They’ll let us ask questions!”