For months the divers of the Salvage Section were struggling with the wrecks in Ostend, clearing the channel, blowing tons of cement out of the _Vindictive_ in order to lighten her, cutting away hundreds of tons of steel so that there should be so much the less to lift. Mighty steel cables were passed under the _Vindictive_ by divers and attached to two lifting craft, one on either side of the ship; two giant pontoons were sunk into place and attached to the hull so that when the time came they could be pumped out and their power used to help lift the stricken ship off the bottom. Some of the compartments in the wreck were made watertight, and after about a year of strenuous toil the task of lifting the structure was undertaken. Pumps were set going, and as the tide rose the shattered British warship came off the bottom and was moved some distance before the falling tide baulked further endeavours. The next day saw the operations carried to a successful conclusion amid scenes of wildest enthusiasm. The raising of the _Vindictive_ signalized the last days of the Naval Salvage Section, but it was by no means the least of the many triumphs that crowned it during the war. CHAPTER IX During the days of the fateful German submarine campaign, the divers of the Admiralty Salvage Section played their part in many a drama, ferreting out clues of vital importance, acting as detectives of the deep. While the _Untersee_ boats of the Germans menaced our national existence and ruthlessly committed many crimes against humanity, the deep-sea detectives of the Salvage Section were always on their track, studying their habits, learning their methods, recovering from watery fastnesses those sealed orders which Tirpitz and his staff would have given anything to keep out of the hands of our alert Admiralty. More than one U-boat, struggling frantically to free herself from the mighty nets in which she had become entangled, found herself caught in a trap from which there was no escaping. The guardians of the nets, going their rounds, marked the agitation of the buoys which told of a giant fish struggling below, and if the prize could not be brought up and captured, a depth charge soon put an end to its struggles.