From the British military harbours and bases on this line close observation of all French Channel ports where transports could be assembled can be maintained by a superior British naval force. Cherbourg and Havre can be controlled from Portland, and Calais and Boulogne from Dover. Flotillas and light craft employed on this service of observation would have their own home base close at hand, and a high proportion could be constantly maintained on duty. The proximity of the battle fleets in the numerous well-protected harbours, where every necessity is supplied, ensures the effective support of the flotillas against any serious attempt to drive them off. 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.