The Jade Channel, which leads to Wilhelmshaven, is exceedingly difficult to navigate, owing to the innumerable and constantly shifting shoals with which it is infested. To keep this channel clear elaborate dredging operations have to be carried on throughout the year, as otherwise it would speedily silt up and become impassable. Access to the harbour is gained through huge locks, most of which can be used, if necessary, as emergency docks for repairing damaged ships. When these locks are closed the harbour is entirely cut off from the sea, thus affording the ships inside complete security against torpedo attack. Commodious as the harbour is, however, it is not large enough to contain the whole fleet, and consequently extra moorings were recently laid outside for cruisers and other small craft. The locks are designed on so large a scale, and are so efficiently operated that several squadrons of big ships can be passed through in a few hours. Wilhelmshaven is the base of the First Battle Squadron, the Scouting Squadron (_i.e._, all the battle-cruisers and other cruisers of the High Sea Fleet), the 2nd Torpedo Division, and of a submarine flotilla. It is very heavily fortified. The approach to the Jade Channel is commanded by the batteries of Wangerooge, an island garrisoned by seamen gunners, and said to have very powerful guns. There is a flying station at Wilhelmshaven, with hangars for a dozen seaplanes. CUXHAVEN Cuxhaven has lately become an important German naval base. Situated as it is at the extreme entrance of the Elbe estuary, it commands the approach to the great commercial port of Hamburg, seventy miles up the river. Cuxhaven has no dockyard of its own, but it possesses a harbour large enough to accommodate great ships of war, and certain facilities for carrying out repairs are provided by the depot of the Hamburg-Amerika Line, of which it is the headquarters. A mile or two west of the harbour are the batteries of Döse, mounting a number of heavy guns and quick-firers. These defences are controlled by the navy, and are garrisoned by five companies of seamen gunners. Although the mouth of the Elbe is wide, only a narrow channel is available for vessels of moderate draught, and the defences have consequently been designed to bring an overwhelming fire to bear on hostile vessels using this navigable approach. For some years Cuxhaven has been the principal mine station of the German navy. It is the base for the mine-laying and mine-sweeping divisions, composed of special ships and a large number of old torpedo-boats equipped for the work. This station is responsible for the observation mine-fields which close the Elbe to hostile ships in war. It contains an artillery depot, a powerful wireless station, and barracks for a large contingent of seamen gunners and marines.