Yet he had to do his duty, notwithstanding his utter distaste for submarine work. He had had no option. The officers of the British Navy volunteer for submarine duties; those of the German Navy are simply told off whether they want to or not.
The nerve-racking work was beginning to tell upon him. His orders condemned him to a forlorn hope, for the English Channel was known to be a death-trap for the under-sea blockaders. The sight of a trawler filled him with feelings akin to terror. The possibility, nay probability, of a merchantman carrying guns made him approach his intended prey with the utmost caution; yet, as he had remarked to Ross Trefusis, he had never torpedoed any vessel flying the red ensign without giving her warning.
But it was not chivalry that prompted Schwalbe to act with consideration. Had he been untrammelled he would have sent his prey to the bottom without compunction, for he had all the brutal instincts of the kultured Hun. It was a superstitious fear that held his frightfulness in check--a presentiment based upon the Mosaic Law, an eye for an eye and a tooth for a tooth.
Having placed a considerable distance between him and his attacker, Kapitan Schwalbe ordered the electric motors to be stopped. The ballast tanks were "blown", and cautiously U75 rose to the surface.
It was the best course open to her. The depth of the water was much too great to allow her to rest on the bed of the sea. On the other hand, in order to keep submerged, the motors would have to be in motion. No one knew better than Schwalbe that the British patrol-boats would be in a position to locate with uncanny certitude the presence of their quarry, unless the strictest silence were maintained by the fugitive.
So, ready to dive at the first alarm, U75 floated awash until such times as were considered favourable for getting under way. Decidedly this part of the English Channel was, for the time being at least, unhealthy; and Kapitan Schwalbe resolved to make for the Bristol Channel, where the dangers of being destroyed by modern mosquitoes were more remote.
Meanwhile Ross and Vernon had been sent back to the quarters in the alley-way, by the side of the motor-room. Not knowing the reason for the U-boat's sudden submergence, and consequently unaware of the danger that threatened her, they formed the erroneous impression that the submarine was about to attack.