Very different is the situation on the sea front against Germany. With the exception of Chatham, no naval base or military harbour exists. Chatham itself has no graving docks for the later Dreadnoughts, and the depth of the Medway imposes serious limitations of tides and seasons upon great vessels using the dockyard. Harwich affords anchorage only to torpedo-craft [and light cruisers], and is lightly defended. The Humber and the Tyne are unsuitable for large battle fleets, and are but lightly defended. Rosyth will not be ready even as a war repairing-base till 1916 at the earliest. Defences are being erected at Cromarty, and a temporary floating base is in process of creation at that point.[[26]] Only improvised emergency arrangements are contemplated for Scapa Flow, and the Shetlands are quite unprotected. The only war bases available for the fleet along the whole of this front are Rosyth, Cromarty, and Scapa—the more remote being preferred, although the least defended. The landing places along the coast are numerous, extensive, and evenly distributed; the strategic objectives open to an enemy are numerous and important. The Shetlands are a strategic position of the highest consequence, totally undefended and ungarrisoned. The same is true of the Orkneys. Edinburgh and Glasgow, Newcastle, Hull, and Harwich are all points of primary importance. No large military garrisons comparable to those on the southern front exist.
But the comparison of the new conditions with the old becomes most unfavourable when we extend our view from the British to the German coast. It is difficult to find any sea front of greater natural defensive strength than the German North Sea coast. Intricate navigation, shifting and extensive sandbanks and currents, strong tides, frequent mists and storms, make the Heligoland Bight a very difficult theatre for oversea operations. The deep re-entrant widening into a broad debouch, flanked at each side by lines of islands and sustained in the centre by Heligoland, confers the greatest possible natural advantages upon the defence. To these have been added, and are being added, everything that military art can devise. Heligoland is an almost impregnable fortress and an advanced torpedo and airship station. Borkum and Sylt are both heavily defended by batteries, minefields, and strong garrisons, and both can be commanded by fire from the mainland. Into this great defended area, with its wide debouch facing towards us, access is given from the Ems, the Elbe, the Weser, the Jade and from the Kiel Canal communicating with the Baltic, and open for Dreadnoughts at the present year. Within this area are all the naval establishments of Germany. A fleet or transports assembled at either end of the Kiel Canal have the widely separated alternatives of emerging either from the Heligoland Bight or from the Baltic for offensive purposes. There would be no difficulty on the declaration of war in assembling unperceived at Hamburg, Kiel, Wilhelmshaven, and other ports, the shipping necessary to transport at least 20,000 men; enough to transport 10,000 men is always in those ports. Large garrisons exist in the neighbourhood, amply sufficient to supply whatever military force was required. The Germans possess to-day large ships of the liner class suitable for transport in a way which the French never did. The rigour with which agents suspected of sending information have been pursued during the last five or six years has made it difficult to arrange for the transmission of intelligence. Consular officers are marked men; and it is to be expected that their communications by the usual postal and telegraphic channels will be delayed if hostilities are imminent. Although the sources from which information may be obtained have been increased in numbers during recent years, and are still being increased as opportunity offers, yet the Admiralty are not prepared to make any confident assertion that a force of upwards of 20,000 men could not be collected in time of peace, and embarked without their knowledge. As a matter of fact, very considerable embarkations of a test character have been carried out without our having any knowledge until some days after the event.
The continuous development of the mine and the torpedo makes it impossible to establish a close watch with heavy ships on the exits from the Heligoland Bight. To do so for a long period of time would mean a steady and serious wastage of valuable units from the above causes, and, if prolonged, would effectually alter the balance of naval power. On the other hand, torpedo craft, which cannot keep at sea like great vessels, and must every three or four days return to port for rest and replenishment, have no base nearer than Harwich, 240 miles away. The operation of controlling the debouches from the Heligoland Bight by means of flotillas would require twice the number of oversea torpedo craft that we now possess. The watch would have to be maintained in three reliefs: one on duty, one in transit, and one at rest, and therefore only a third of the existing vessels would be available at any given time. Such a force could be overwhelmed by a sudden attack of two or three times their numbers by a well-chosen blow, opportunities for which would frequently recur. Unless, therefore, we were to take by storm some fortified German island which could be held as a base, or were permitted to use Dutch or Danish territory, the closing of the debouches of the Heligoland Bight by a close flotilla cordon is, in the opinion of the Admiralty, impracticable at present.
The development of submarines of ocean-going capacity may be expected to modify this situation in our favour.
The problem of controlling the alternative debouches from the Baltic by watching over the Skaw or the Belts presents many of the features that have been found so unfavourable in regard to the Heligoland Bight. Nothing effective could be done, or still less maintained, with our present forces without using the territory of Norway or Denmark, or both. It must be borne in mind that the enemy have the option of striking with their whole force on either line.
On the assumption that a close blockade, either of the Heligoland Bight or of the exits from the Baltic, is not possible, the Admiralty cannot guarantee that individual vessels will not frequently slip through the cruiser squadrons patrolling the wide area of the North Sea. The North Sea comprises an area of more than 125,000 square miles. The number of cruisers available is less than 30, of which a large proportion will always be recoaling. The aid that can be given at a distance from the British shore by torpedo craft would be partial and fleeting. The weather is frequently thick; on a third of the days in the year the visibility is not more than 4 miles; on a quarter of the days in the year it is not more than 2 miles. There are about five days fog per month during the year. April averages ten days fog. At night it is frequently impossible to see a ship without lights at more than a few hundred yards distance, and often not at that. It is no exaggeration to say that the main risk which a single fast ship would run, steaming at night without lights, would be that of collision, which chance may be very well accepted. It will be easy to demonstrate this by experiments at the forthcoming manœuvres. If, therefore, close and certain observation becomes impossible, there is a very good chance of an indefinite succession of individual transports reaching the British coasts without being intercepted by the controlling cruiser squadrons.
Let us now consider what arrangements exist or are possible along the line of the British coasts to detect and attack such vessels.
Four flotilla cruisers, seventy-four destroyers and torpedo-boats, and eighteen submarines are placed under the command of the Admiral of Patrols for the defence of the East Coast from the Shetlands to Dover; less than 100 vessels and more than 600 miles of sea front. It is quite impossible with such a small force to maintain a regular patrol, or still less a line of observation. These flotillas are not intended for observation, but to attack. To employ them on the former service, for which their numbers are wholly insufficient, would speedily exhaust them: at least half would have to be resting and refuelling. It is not possible with the forces available for the patrol flotillas to prevent enemy vessels from reaching the British coast. Our dispositions are intended to make it certain that they will be attacked in force with the least possible delay.
A curious distinction attaches to the work of naval coast defence. Usually the line of observation lies in advance of the line of resistance. In coast defence the line of observation is in rear of the line of resistance. So far as the patrol flotillas are concerned, the British coasts are themselves the only true and certain line of observation. The approach of an enemy may be undetected by the cruising squadrons or by the patrolling flotillas. But it ought to be certain that his first contact with the coast at any point is reported to the Admiral of Patrols, and that that officer will have his available forces massed at convenient points from which an attack can be at once delivered. The Admiral of Patrols must treat his problems selectively and recognise that absolute certainty is out of reach, that his flotillas are for fighting purposes, and that their rôle of scouting is secondary. It is of very little use reporting the approach of an enemy when one has not the forces with which to strike him. The patrol flotillas are therefore kept in hand at the best strategic points, neither scattered nor exhausted, and a system of land observation by outposts, cyclists, aircraft and signal stations, all connected by telephone, ought to be perfected, from which accurate information can be transmitted to the points where the patrol flotillas are massed.