“She’s tacking so as to come close aboard of us,” declared Tom.  “Shall I shift the course, Jack?” he inquired.

“I don’t think so,” answered Jack.  “Of course under the pilot rules of the United States, a power boat under way must keep clear of a sailing vessel.  She has the right of way and seems to be taking it.  But we can easily dodge her with our powerful engines.”

Closer and closer came the schooner until it seemed that she would surely collide with the motor-boat.  When scarcely more than a length Away from the Fortuna, the schooner was brought sharply about on the other tack.  As she came about a clear cut whistle sounded shrilly in the morning air: 

“Bob White!  Bob, Bob White!”

“Gracious!” cried Frank springing to his feet.  “The Bob White.”

Instantly he was on deck sending ringing across the water his answer to the challenge of his Patrol: 

“Bob White!  Bob, Bob White!”

The men on the schooner laughed coarsely as the boy waited for an answer to his challenge.  The two vessels were drawing farther apart now.  Their voices were indistinguishable, but once more came the call: 

“Bob White!  Bob, Bob—­”

Suddenly the call stopped as if a hand had been placed over the face of the one making the cry.  The crew of the Fortuna stared at one another in wide eyed wonderment.  They all were thinking rapidly and each seemed to have formed the same conclusion.

“Shall I follow them, Captain?” asked Tom addressing Jack.

“I’d like to,” Jack replied, “but I don’t think it wise.  It may be that Charley Burnett is aboard that, schooner and that the schooner is the one that chased and fired at us yesterday.  We are not sure of either supposition.  If he’s aboard, he’s still alive.  If he was not on board and one of the crew did the whistling, we would have our trouble for our pains and be laughed at and perhaps insulted into the bargain.  We’d better wait a while, I think.”

“But maybe he is there and wants to get off,” declared Arnold.

“Possibly,” agreed Jack.  “But in that case if we were to attempt to rescue him by force, that crew is too powerful for us to overcome unless we run alongside and shoot them down mercilessly.  We are not prepared to do that just yet, I hope.  What’s your idea concerning, this, Frank?” he continued addressing his friend.

“It’s pretty hard to say it, but I really believe you’re right, Jack,” answered Frank holding out his hand. “’You are right.”

“Thank you,” said Jack.  “I believe this thing will come out all right without any serious harm to your chum or to us.”

If Jack could only have looked into the future he might not have spoken so confidently nor have believed his own words so much.

The run back to the harbor occupied but little time.  Arrived there Jack at once went ashore to arrange for hauling out and repairing the Fortuna.  He found the marine railway without difficulty but was unable to secure accommodations for his motor boat at once.  Every berth was full but one would be empty later in the day.