Unhesitatingly the greatest salvage experts in the world would have pronounced her lost beyond recovery. She was 100 feet deeper than the British record dive of 210 feet, a depth which no other divers in the world had ever reached, and she was far deeper than any craft hitherto lifted from the seabed. The experts of the American Navy, aware of these and other facts, knew that they desired to achieve the impossible, but instead of admitting that it could not be done they straightway set about doing it. A big rise and fall in the tide would have been of tremendous assistance to them, but at Honolulu the tide rises and falls only 18 inches. It was of no help to them at all. So they made their plans to haul her up bodily by winches and tow her into shallower water until she grounded; while for the last stage of the journey into the harbour they placed their faith in six pontoons, each sheathed in a jacket of timber 4 inches thick to prevent the cables from cutting it. This stout timber casing successfully protected the pontoons from all damage when they were brought into play. Nor was it unnecessary, for, incredible as it may seen, the chafing of the submarine during a sudden gale quickly wore through the mighty steel cables as she rubbed them against the bottom. It was in connection with the cables that the greatest diving feat in all history was accomplished. The cables were swept underneath the submarine by surface craft in the usual way. But the salvors could not be sure that the cables were exactly where they ought to be. With cables too near the bow and the stern, the submarine would just fold up as she was lifted and break her back, the two halves, falling apart, probably defying recovery. Even if they could be raised, the damage would be so great that all traces of the original accident would be destroyed and the experts could never learn why the submarine had foundered. The one way of finding out whether the cables were properly in place was to send down divers to see. A diver in Lake Huron in the ’nineties, trying to recover sunken treasure, was crushed to pulp at a depth of 198 feet; even a diving bell, operating later on the same wreck, was unable to withstand the pressure, consequently it seemed like sentencing a man to death to order him to dive to a depth of 304 feet. However, the cleverest diving expert in the American Navy pondered over the matter and, in the light of recent experiments, considered it could be done provided all the rules were most rigidly observed. The finest divers in the American Navy, men who had been specially trained, were thereupon sent to Honolulu to carry out this gigantic task.