A week later the Capella returned to Southampton to replenish her stores, and after three days in port she received orders to proceed to the French coast and patrol off Cape Levi, where the presence of a hostile submarine had been reported.
This intelligence was serious. It meant that, once again, an unterseeboot had made its way into the English Channel, and was lying on the track of the British transports and hospital ships running between Southampton and Rouen.
It took the Capella two hours only to run from The Nab to within sight of the French coast. Even then her motors were not running at the maximum number of revolutions. Extreme speed was only resorted to when actually engaged in submarine hunting.
As the vessel closed with the grey cliffs of Normandy, Ross suddenly shouted: "Submarine on the port bow!"
Less than two cables' length away could be discerned the twin periscopes and a portion of the conning-tower. The submarine was not forging ahead; it was simply stationary, except for a slight movement caused by the action of the waves. It certainly was not a British craft. It might be French. The odds were that it was German, since submarines belonging to the allied nations were not in the habit of keeping awash, unless in the presence of an enemy.
Quickly the guns, which were already cleared for action, were trained upon the visible part of the submarine; but as she made no attempt to move, Captain Syllenger refrained from giving the order to open fire.
Thrice the Capella circled round the mysterious craft, at the same time gradually closing, since she had nothing to fear from the discharge of a torpedo.
"I believe she's abandoned, sir," said Barry.
The Capella stopped. Preparations were being made for the lowering of a boat, when one of the seamen shouted:
"It's a dud, sir; a blessed decoy-bird!"
The man was right. Upon investigation, the submarine was found to be nothing more than a couple of barrels covered with painted canvas. Two thick poles passing vertically through them, and weighted at the lowermost ends to give the necessary stability, served as periscopes.
"There's a real submarine knocking about, I'll swear," said the skipper. "Put a shot into those barrels, Morgan."
One shell was sufficient. Little more than a hundred chips floating on the surface was left of the decoy.
The Capella was about to resume her course when a warning cry was heard:
"Torpedo coming, sir!"
From a point bearing half a mile on the vessel's port quarter, the track of the on-coming torpedo was clearly discernible. The Capella, being without way, would undoubtedly have fallen a victim had it not been for her light draught, for before she could forge ahead the missile passed under her keel. Its track could be followed as far as the eye could reach, which showed that it was a modern weapon propelled with superheated air and having a range of about five miles.
Straight for the source of the missile, tore the British craft, but her effort to grapple with the unterseeboot was in vain. The submarine had dived immediately. No sounds betrayed her presence in the vicinity. Had the U-boat been moving, the churning of her propellers would have been distinctly audible.
"She's got away, worse luck," growled Sub-lieutenant Fox. "I wonder how she did it? It's too deep for her to sound, and she can't be moving under her own power."
"We'll have her right enough," rejoined Barry, the optimist. "A light haze and a calm sea is what we want. We'll run her down in less than a week, you mark my words."
Four days passed. The Capella kept her station almost without incident. Ship after ship, deeply laden with troops and munitions, entered the sand-banked estuary of the Seine, having been escorted thus far by destroyers. Ship after ship, more lightly burdened, left the river, homeward bound. Amongst them were hospital ships, clearly distinguishable by their broad green bands and conspicuous red crosses on both bows and quarters. A big action had taken place "somewhere in France", and the passing of the Red Cross vessels was the aftermath of a dearly-bought victory.
Yet nothing occurred to threaten the constant stream of shipping. It seemed reasonable to surmise that either the U-boat had met with an accident or else that she had transferred her energies to another area.
Meanwhile Ross and Vernon had been working hard, improving their seamanship. Under the instruction of the two sub-lieutenants they were making rapid progress in navigation; they could fix their position by the use of a sextant, were able to use the semaphore, and, generally, competent to carry out the duties required as midshipmen of the watch.
Captain Syllenger had long before overcome his prejudices against the sons of Flag Officers—at least in their case—and even expressed his willingness to grant them each a certificate of proficiency, should they wish to transfer to one of the cruisers of the Royal Navy.
At length the Capella received orders for recall to her station off Beachy Head. She was to put into Havre to revictual that day, leaving at 9 a.m. on the morrow.
The lads were heartily glad when the Capella left the malodorous bassin à flotte. The irksomeness of lying in the harbour at Le Havre palled upon them, even after a few hours. They yearned for the open sea almost from the time their ship made fast alongside the grimy quay.
Forty minutes after leaving French waters, the Capella sighted a large cargo-boat steaming northwards. She was high in ballast and rolling like a barrel. On bringing glasses to bear upon her, the Capella's officers found that she was the Orontabella, one of the vessels chartered by the British Government and fitted as a horse-transport ship. She was doing 16 knots to the Capella's 34, and when first sighted was nearly five miles off.
Suddenly a low rumble was heard by the crew of the patrol-vessel. Telescopes and binoculars that had just been laid aside were again brought into action, and it was seen that the transport was sinking rapidly by the stern. She had been torpedoed under the starboard quarter. The terrific impact of the explosion had torn a large hole, besides shattering the rudder and one of the propellers, while all her boats in davits were rendered useless by the concussion.
It was a matter of but a few moments before she made her final plunge. Already signals were fluttering from her stumpy masts—the well-known N.C. (in distress; want immediate assistance) and A.R. (boats are stove in).
Captain Syllenger gave a quick glance astern. There were other vessels, but low down on the horizon. To expect succour from them was for the present out of the question. He had a double task: to attempt to destroy the aggressor, and to rescue the transport's crew.
"Prepare to lower boats!" he shouted. "A midshipman and a couple of hands in each. Guns' crews stand by!"
Clang, chang, went the engine-room telegraph. Like a greyhound, the Capella increased her speed, until she was within a quarter of a mile of the foundering vessel. Then reversing engines, she almost lost way at less than a cable's length from the transport.
By this time Ross and Vernon were in their respective boats. Before way was off the ship the falls were paid out and the disengaging gear cast off.
"Give way, men," ordered Ross.
His scanty crew, for more men could not well be spared, "gave way" with a will, gaining a couple of lengths before his chum was able to push off.
With hardly a pause the Capella dashed off, quickly increasing her pace to full speed ahead, in her quest for the U-boat that had launched the deadly torpedo.