The salvage of "Squalus" was commanded by Rear Admiral Cyrus W. Cole, Commander of the Portsmouth Naval Shipyard, who supervised salvage officer Lieutenant Floyd A. Tusler from the Construction Corps. Tusler's plan was to lift the submarine in three stages to prevent it from rising too quickly, out of control, with one end up, in which case there would be a high likelihood of it sinking again. For 50 days, divers worked to pass cables underneath the submarine and attach pontoons for buoyancy. On 13 July 1939, the stern was raised successfully, but when the men attempted to free the bow from the hard blue clay, the vessel began to rise far too quickly, slipping its cables. Ascending vertically, the submarine broke the surface, and of the bow reached into the air for not more than ten seconds before she sank once again all the way to the bottom. Momsen said of the mishap, "pontoons were smashed, hoses cut and I might add, hearts were broken." After 20 more days of preparation, with a radically redesigned pontoon and cable arrangement, the next lift was successful, as were two further operations. "Squalus" was towed into Portsmouth on 13 September, and decommissioned on 15 November. A total of 628 dives had been made in rescue and salvage operations.