Suddenly Vernon touched his chum's elbow, as a faint pin-prick of light glimmered twice. It was the shore agent's signal that the coast was clear.
Barely carrying steerage-way, U75 stood in towards the as yet invisible Port Treherne. Already her crew had brought the collapsible canvas boat from below, "man-handling" it through the fore hatch. The men, having opened it out and shipped the felt-lined and well-greased rowlocks, stood by to launch it.
Gradually the towering cliffs enclosing the creek became distinguishable against the loftier background of gaunt hills. Into the gap the submarine crept with the utmost caution, until it seemed as if she were on the point of running her nose against the sheer face of the granite wall. The water bubbled slightly as her motors were reversed; then, turning in her own length, she brought up, with her bows pointing seawards.
Three of the crew grasped the canvas boat and pushed it gently into the water on the port side. One of them clambered in and shipped the oars in the row-locks.
The two lads were cautiously scanning the shores of the inlet. Ross could sniff the unmistakable Cornish air. The call of home seemed irresistible. It looked a comparatively easy matter to slip quietly over the starboard side, and swim with noiseless strokes towards the weed-covered rocks that showed six feet or more above the sea. It was half ebb-tide; there was little or no drift out of the cove. Under the shadow of those dark cliffs detection seemed almost impossible, unless the submarine went to the risky expedient of switching on her search-light.
They moved stealthily towards the light wire railing on the starboard side just abaft the conning-tower. Everything seemed in their favour. Kapitan Schwalbe and the Unter-leutnant were on the navigation platform, peering through their night-glasses towards the flat rock that served as a landing-place. Two of the seamen were engaged in coiling down a hand-lead line; the rest of the men on deck were devoting their attention to the now departing canvas boat.
"Not so fast, my friends," exclaimed a low deep voice, which the lads recognized as that of Kapitan Schwalbe. "Remember I have a pistol ready to hand."
"How in the name of goodness did he know what we were up to?" thought Ross.
The chums stood stock-still. They felt much like children found out in some petty escapade.
"Koppe! Where are you?" asked the Kapitan in a loud whisper.