The submarine was Germany's best weapon. She outmatched the Allies on land, but in such a small degree that her most brilliant effort could not win a decisive victory. Meanwhile her opponents grew stronger in an economic way, while the situation in Germany became more strained. By issuing a constantly increasing volume of bank notes against an almost stationary gold reserve she depreciated the value of her mark at home and abroad. In the face of this tangled situation her submarines rendered incalculable aid, destroying and menacing allied commerce. Without them Germany would have been helpless upon the sea, would have ceased to exist as a maritime power. Her first-line ships lay securely in their harbors, unable to venture forth and match the longer-ranged, heavier-gunned vessels of the British, ably supplemented by the French fleet. Just how many submarines Germany possessed at the beginning of the war cannot be stated. The number probably was in the neighborhood of fifty. That she has lost many of these vessels and built even a larger number is certain. As the conflict grew older Great Britain in particular learned a method of combating them. It was estimated that on August 1, 1915, she had 2,300 small craft specially fitted for running down submarines. Private yachts, trawlers, power boats, destroyers, and torpedo boats hunted night and day for the elusive undersea boats of her enemy. The pleasure and fishing craft which had been impressed into service were equipped with all sorts of guns, some of them very old ones, but thoroughly capable of sinking a submarine. These vessels patrolled the British coast with a zeal that cost Germany dear. Some authorities believed that up to August 1, 1915, upward of fifty German submarines had been sunk and more than a dozen captured. The numbers probably are excessive, but if they had disposed of even twenty-five undersea boats the effort was a distinct success. In addition to this means of defense Great Britain embarked upon another undertaking that truly was gigantic in its extent and the difficulties imposed. She stretched wire nets for many miles under the surface of the waters washing her shores. The regular channel routes were thus guarded. Once within such a net there was no escape for the submarine. The wire meshes fouled their propellers or became entwined around the vessels in a way that rendered them helpless. The commander must either come to the surface and surrender or end the career of himself and crew beneath the waves. A number of submarines were brought to the surface with their crews dead by their own hands. Others were captured, and it is said that about twenty of these vessels have been commissioned in the British navy.