It will be readily understood that little reliance could be placed on large conspicuous buoys laid by us near the enemy's coast. On discovering such navigational marks the enemy would presumably either move them a mile or so, for the purpose of interfering with our navigation, or else remove them altogether. Buoys, to be of any practical use, must be conspicuous, hence the likelihood of their being seen by the enemy unless placed in position at the last possible moment. This alternative was actually followed; it does not require much imagination to realise the difficulties and dangers in placing them in readiness for the operation and in removing them again on each occasion when the operation was postponed.
The strong tidal stream in the southern portion of the North Sea renders navigation rather anxious work in misty weather, or in darkness, especially as the normal rate of the current is much influenced by weather. Naturally, there is less danger of hitting a shoal which one is endeavouring to avoid, if the ship is steaming either directly with or against the current; the error in such cases is confined to the time at which any particular position will be reached. But when steaming across the current a small eccentricity on the part of the latter may make all the difference between reaching the desired position and missing it altogether. The current running parallel to the Belgian coast attains a speed of about three knots under normal conditions. Should a three-knot allowance be made when steaming across the tide there would be a serious error of position at the end of an hour's run if the tidal stream happened to be running at the rate of two and three-quarters or three and one-quarter knots; it must be realised that a ship cannot discover the rate of the tidal stream in a given area until she has completed her passage through it; i.e., until she has already suffered from its eccentricities.
For the purposes of the particular case under review it was necessary for the expedition to arrive at an exact position, thus tidal calculations and navigational aids assumed great importance. But they alone were insufficient to ensure accurate navigation. Compasses must be correct, or their errors known, and the speed of the ship due to its own engines requires to be carefully gauged. For a given speed of engine the speed of a ship varies according to her draught and the state of the ship's hull under water. All these considerations will serve to show the extreme necessity for working out courses, speeds, and times beforehand with the utmost accuracy, for repeatedly checking them to ensure the absence of clerical error, for reconsidering allowances for the vagaries of the elements, and for correcting the results from day to day according to the tidal differences due to the ever-changing phases of the moon. The careful navigator always follows a similar procedure, but, in ordinary cases, he knows that a fault in position can probably be remedied in time to avoid untoward incident. In our movements, however, there would be small chance of remedy if the blockships failed to find the canal entrance, or if the submarines were unable to locate the viaduct, or if the storming vessels missed the Mole.
Clearing the Mines
Preparation for the passage across the seas involved yet another matter of considerable importance. Vast numbers of mines had been laid, both by ourselves and by the enemy, during the previous three and a half years, in the areas through which the expedition must pass before reaching the permanent German defence mine-fields near the Flanders coast. Doubtless other mines had dragged with the tide across our desired route. Special mine-sweeping work was, therefore, necessary to render the major portion of the passage even tolerably safe from mines. The reader can probably appreciate the difficult nature of that task with its attendant risks and necessity for thoroughness.
In addition to the one hundred and sixty-two vessels whose duties have been mentioned, other supporting squadrons were necessary far out at sea. The possibility of our intentions having become known to the enemy had to be borne in mind. In such an event the enemy would, of course, adopt special measures to ensure giving the expedition a warm reception on arrival, but a most important eventuality for us to guard against was that of meeting a superior concentrated enemy force already at sea waiting to intercept us en route. Scouting craft, both aerial and naval, were therefore required; it was also advisable that our fighting fleet should be conveniently situated in case the chance arose of defeating any such counter to our expedition.
German High Seas Fleet
Whenever we employed our small craft to operate in enemy waters we had to bear in mind a certain possibility. The enemy on becoming aware of our movements, or intentions, and perhaps feeling unusually courageous, might say, "Here are a number of small enemy vessels close to our harbours, let us engage them with the whole strength of our fleet and thereby achieve a great victory for the Fatherland." And so, in case the German Fleet left their harbours, unlikely though it might be, our Grand Fleet was always "in the offing" at such times ready to meet the so-called High Seas Fleet and send them down to the place where they ought to go.
The man-in-the-street must have wondered what the Grand Fleet was doing at sea so often in view of the fact that the enemy hid themselves almost throughout the war. The difficulty lay in the fact that we could not be perfectly certain that the constitution of German naval valour would continue to include ninety-nine per cent of discretion. Time after time the Grand Fleet hoped against hope that they might meet the enemy. The operations off the Belgian coast seemed to hold out yet another slender hope; this, pardon the anticipation, proved to be as forlorn as usual. The history of the High Seas Fleet, with respect to their oft-repeated desire to try conclusions with the Grand Fleet, can be briefly narrated. In the four and a quarter years following the outbreak of war the High Seas Fleet came out once, and once only, with the express intention of meeting the Grand Fleet—and that was to surrender! On the one other occasion when they met our fleet, incidentally by accident, they concentrated all their efforts at escape and then claimed the victory. The German Navy never had any traditions—now they have one less!