By this time the fast gunboat “Oakland,” which had a safe speed of twenty-four knots an hour, under forced draught, lay to, some two miles further out.  The “Oakland’s” task was to stick close to the leaders, and, at the end, to decide which craft had won.

Boom! The first gun sounded over the starboard side of the “Chelsea.”  In five minutes’ time the second gun would thunder out—­and the racers would be off!

Such a scurrying as there was then among these five little craft of war!

Captain Jack Benson had the wheel again.  Henceforth, Lieutenant Danvers was to be but a spectator—­a judge, at need, and on his honor, as an officer of the United States Navy, to show no partiality to those on whose boat he found himself.

As Eph might be needed on deck, at any instant, he stood leaning against the conning tower.

David Pollard was missing.  He had gone below, had taken off his coat, and was standing in shirt-sleeves, ready to render any possible aid to Hal Hastings, the young chief engineer on whom so much depended in the six hours to come.

Now that one of the supreme moments in his career had come, Jacob Farnum hardly dared breathe.  He said not a word to Eph, who, just as anxious, stood at his elbow.

As the submarine craft scurried over the waves, each seeking its best place for a start over the line, the “Zelda” came up within sixty yards, running alongside for a moment or two.

John C. Rhinds, standing at the rail of his own craft, with what was intended to be a smile his face, waved his hat wildly at Jacob Farnum.

“Good luck to you, Farnum—­and to us!” bellowed Rhinds.  “Of course, I’d like to win today, but if you’ve the better boat, go ahead and leave us at the finish.  May the best craft win, no hard feelings!  Fair sport all the way through, Farnum, old and to you, Benson—­may you never be in fitter shape than to-day!”

“The old hypocrite!” gasped Jack, vengefully “I’m mighty sorry I can’t head this boat around and run it straight down his lying throat!”

“Then he’d surely gobble you up!” laughed Lieutenant Danvers.  “But be careful, lad!  Don’t let vengeful thoughts get into your head and stick to-day.  You’ve got to keep yourself cool and your nerve steady.  Look out, now, for the second gun!”

All five of the submarines were manoeuvering for the starting line.

Boom!  The second gun roared out, and the six hours’ speed and endurance test was on!

CHAPTER XI

THE STRAIN OF RED-HOT METAL

First over the line passed the “Zelda,” but it was a fair get-away.  How her propellers churned the foam now!

Just as it happened, and through no fault of handling, Jack Benson got the Pollard craft over the line third.  At the outset, therefore, his boat was distanced some twenty-four seconds by the leader.