It seemed that the disguised undersea boat mounted four guns on her deck, but she was a slow sailer. She had moved up close to the schooner before showing her teeth.
Then she dropped two shells near the _Hattie May_ to show the skipper that she had the range of his schooner. He had to surrender, and the U-boat moved up and gave him and his crew ten minutes to get into the boats. Then they sank the _Hattie May_ by hanging bombs over her sides and exploding them simultaneously by an electric arrangement.
The skipper of the schooner was taken aboard the U-boat and said he was shown all over the ship. The German captain seemed to be inordinately proud of his craft and what she could do.
"She's got torpedoes, but she don't use 'em because they are expensive," said the skipper. "They are saved for a last resort. But she is a mine layer, for I saw two wells and saw the mines, too. She has been out five weeks and is numbered U-Two Hundred Fifty."
"Two hundred fifty!" gasped Whistler to his chums, who were hanging over the rail to listen to this report. "What do you know about that?"
"That's the very number that man Blake used in the restaurant, talking with the skipper of the oil tender, wasn't it?" asked Frenchy of the quick memory.
"You mean Franz Linder, the German spy!" ejaculated Torry, with emphasis. "He spoke of this very sub."
The steamer's wireless operator was sending out an S O S call and a destroyer quickly answered. The steamer remained by the two boats from the sunken schooner until the fast-flying naval vessel appeared in the west.
After that the boys on the steamer kept their eyes open for sight of the camouflaged U-boat. As the boat picked up speed again and kept to her course. Whistler Morgan and his mates discussed the matter with much excitement.
"Do you s'pose Mr. MacMasters will let us shell the Hun?" demanded Frenchy eagerly.
"She'll more likely shell us," declared Torry, inclined to be pessimistic.
"I bet we can run away from her," cried Ikey Rosenmeyer.
"Say! this tender is no sub chaser. In a race with the S. P. 888, for instance, she wouldn't have a chance."
"Aw, well," Frenchy broke in, "that U-boat will not have a speed of over fourteen knots on the surface. We can do better than that."