The German torpedo-boat had hoisted four signal-flags to her cross-yards. They were blowing out in a fore-and-aft direction.
"Can't make them out," declared Kenneth, "and wouldn't understand them if I did. Now, watch."
Suddenly two spurts of flame burst from the deck of the pursuing boat. Shells from her three-pounder quick-firers pitched a short distance on her starboard side. Simultaneously the torpedo-boat swung round. Travelling at twenty-seven knots, the sudden porting of her helm caused her to heel outwards till her deck was almost awash.
"By Jove, she's rammed our boat-hook!" shouted Kenneth enthusiastically. "If ever she gets back to port, won't she pitch a yarn about ramming and sinking a British submarine!"
The lad was not wrong in his surmise, for the torpedo-boat slowed down and made a complete circle, steaming over the spot where she imagined the periscope to have been. Luckily the ruse was not discovered, for a chance shot had shattered the boat-hook staff and had sent the weighted end to the bottom; while, on the other hand, the motor-boat had gained at least two miles on her pursuer.
"It's worth while throwing our remaining boat-hook overboard," said Rollo. "I don't suppose we'll want it in any case."
The German torpedo-boat had now resumed the pursuit. Obviously fearing the presence of other submarines she kept a zigzag course, altering her helm every five minutes in order to confuse the aim of a possible torpedo-gunner. Consequently, although she still overhauled her quarry, the distance between them lessened with perceptible slowness.
Ten minutes from the time of resuming her course the torpedo-boat fired her bow gun. The plugged shell, purposely aimed wide, threw up a column of spray a hundred yards from the motor-boat's port quarter.
The lads exchanged glances. Kenneth leant forward and switched off the ignition.
"Hard lines!" he ejaculated. "If it weren't for the girls——"