The nature of naval operations necessitates the expenditure of fuel, ammunition, and supplies; wear and tear of machinery; fatigue of personnel; and a gradual fouling of the bottoms of the ships. In case actual battles mark the operations, the expenditure of stored-up energy of all kinds is very great indeed, and includes not only damage done to personnel and material by the various agencies of destruction, but actual loss of vessels.
To furnish the means of supplying and replenishing the stored-up energy required for naval operations is the office of naval bases.
A naval base capable of doing this for a large fleet must be a very great establishment. In such a naval base, one must be able to build, dock, and repair vessels of all kinds, and the mechanisms needed in those vessels; anchor a large fleet in safety behind adequate military and naval protection; supply enough fuel, ammunition, and supplies for all purposes, and accommodate large reserves of material and personnel. Inasmuch as a naval base is purely a means for expending energy for military purposes, and has no other cause for its existence, it is clear that it cannot be self-supporting. For this reason it is highly desirable that a naval base shall be near a great city, especially if that city be a large commercial and manufacturing centre.
It is true that many large naval bases, such as Malta and Gibraltar are not near great cities; and it is true that most large naval bases have no facilities for building ships. But it is also true that few large naval bases fulfil all the requirements of a perfect naval base; in fact it is true that none do.
The most obvious requirement of a naval base is a large sheet of sheltered water, in which colliers and oil-carriers may lie and give coal and oil to fighting craft, and in which those fighting craft may lie tranquilly at anchor, and carry on the simple and yet necessary repairs and adjustments to machinery that every cruising vessel needs at intervals. Without the ability to fuel and repair, no fleet could continue long at work, any more than a man could do so, without food and the repairs which nature carries on in sleep. The coming of oil fuel and the consequent ease of fuelling, the practicability even of fuelling in moderate weather when actually at sea, subtract partially one of the reasons for naval bases; but they leave the other reasons still existent, especially the reasons connected with machinery repairs. The principal repair, and the one most difficult to furnish, is that given by docking in suitable docks. The size and expense of docks capable of carrying dreadnaughts and battle cruisers are so great, and their vulnerability to fire from ships and from aircraft is so extreme, that the matter of dry-docks is perhaps the most troublesome single matter connected with a naval base.
The necessity of anchorage areas for submarines is a requirement of naval bases that has only recently been felt; and the present war shows a still newer requirement in suitable grounds for aircraft. The speed of aircraft, however, is so great that little delay or embarrassment would result if the camp for aircraft were not at the base itself. Instead of the camp being on Culebra, for instance, it might well be on Porto Rico. The extreme delicacy of aircraft, however, and the necessity for quick attention in case of injuries, especially injuries to the engine, demand a suitable base even more imperiously than do ships and other rugged things.
That the vessels anchored in the base should be protected from the fire of ships at sea and from guns on neighboring shores is clear. Therefore, even if a base be hidden from the sea and far from it as is the harbor of Santiago, it must be protected by guns, or mines, or both; the guns being nearer to the enemy than are the ships in the waters of the base. An island having high bluffs, where large guns can be installed, and approached by gradually shoaling waters in which mines can be anchored, with deeper water outside in which submarines can operate, is desirable from this point of view.
Ability to store and protect large quantities of provisions is essential, and especially in the case of ammunition and high explosives. For storing the latter, a hilly terrain has advantages, since tunnels can be run horizontally into hills, where explosives can lie safe from attack, even attack from aircraft dropping bombs above them.
Naturally, the country that has led the world in the matter of naval bases is Great Britain; and the world at large has hardly yet risen to a realization of the enduring work that she has been quietly doing for two hundred years, in establishing and fortifying commodious resting-places for her war-ships and merchant ships in all the seas. While other nations have been devoting themselves to arranging and developing the interiors of their countries, Great Britain has searched all the oceans, has explored all the coasts, has established colonies and trading stations everywhere, and formed a network of intimate commercial relations which covers the world and radiates from London. To protect her commercial stations and her merchant ships from unfair dealings in time of peace, and from capture in time of war, and to threaten all rivals with defeat should they resort to war, Great Britain has built up the greatest navy in the world. And as this navy pervades the world, and as her merchant ships dot every sea and display Great Britain's ensign in every port, Great Britain has not failed to provide for their safety and support a series of naval stations that belt the globe.
Bases are of many kinds, and may be divided into many classes. An evident ground for division is that of locality in relation to the home country. Looked at from this point of view, we may divide naval bases into two classes, home bases and distant bases.