After passing over the well-known buoys at the approaches to the harbour, we crossed a fleet of trawlers in the emergency war channel busily engaged in the pleasing task of sweeping up enemy mines laid the evening before by an optimistic Fritz from Zeebrugge. Fifteen minutes later we had the Shipwash four miles on our port beam, and were over the shipping channel which ran parallel with the coast. Here, as far as the eye could see in either direction, was a thick stream of cargo boats, of all shapes and sizes, ploughing along on their various occasions, a striking example of the might of the British Mercantile Marine.
My ears were now deadened to the noise of the engines, and I would not hear them again unless something went wrong and the note changed. I had got the feel of the controls and was flying automatically, and was unconscious of being in the air. It was merely like rushing over a very calm sea in a fast motor-boat, except for the absence of shocks and the wide horizon.
Leaving the shipping channel behind we pushed on into the open sea. Presently Holmes slapped me on the shoulder and pointed over the starboard bow. Some seven miles away were four white waves rushing across the surface of the water, apparently without any means of propagation. Taking my hands from the control-wheel I made the signal "wash-out," on recognising the bow-waves of four destroyers in line ahead pushing through the water at top speed, although the low, slim, grey ships were invisible, and of course no Huns would be playing about in such dangerous parts.
The wireless operator came forward—for the crew of a flying-boat can move about easily and change places if necessary—lifted the flap in the side of my flying-cap, and shouted in my ear "Hun submarine working. Heading towards her." All the four of us were now keeping a keen look-out, my own method being to swing my head from side to side with a slow steady motion, thoroughly searching the half-circle of the horizon, keeping my eyes focussed for a distance of four miles, as this was the average distance for sighting submarines, although they have been sighted from a distance of fifteen miles.
And then I saw a black speck on the water dead ahead. Involuntarily I shoved down the nose of the boat and opened out the engines. And then I saw that it was the North Hinder. As we passed over her the Dutch flag at her stern was politely dipped in salute. Changing course here we boomed off towards the Schouen Bank buoy on the first arm of the Spider Web.
Suddenly, with a nerve shock, a pleasant tingling which cannot be described, I saw a submarine dead ahead, about five miles away, fully blown, and running directly towards us. Slamming on the engines, and pushing the controls forward so as to lose height and gain the maximum speed quickly, I hurled the 4½-ton machine through the air towards the submarine at a mile and a half a minute.
As our own submarines operated in this area I did not know whether it was a Fritz, but fervently hoped it was.
I noticed that it was running at about six knots, in which case it was probably a Hun travelling on one engine and charging the batteries with the dynamo on the other. The submarine statement received from the Naval authorities the evening before had not mentioned one of our own submarines as working in this vicinity, but then submarines were a law unto themselves as regards time and navigation, and had a habit of appearing in the most unexpected places.
With the opening of the engines, the signal for action stations, the engineer thrust himself up in the rear cockpit and seized the stern guns in case hostile seaplanes had been sighted, the wireless operator quickly wound in his trailing aerial to prevent it being carried away if the boat came down near the water, and Holmes, who had seen the submarine, ducked into the front cockpit. He snapped back the lever which removed the safety device from the bombs and set the bomb-sight for height, speed, and wind.