Between 1924 and 1931 his Cox & Danks Shipbreaking Co. successfully raised 35 ships of the German Imperial Navy High Seas Fleet that had been scuttled at Gutter Sound, Scapa Flow, in 1919.
Deciding that anyone who could put electricity into people's homes would become rich, Cox was determined to be just that, and moved to the post of Assistant Engineer at Leamington, and from there to Ryde Corporation on the Isle of Wight.
Fatal accidents on the wreck of the White Star liner Celtic (stranded on the Cow and Calf rocks, adjacent to Roches Point, off Cobh, Ireland in 1929), took some of the drive out of Cox, for he respected his workers and treated them accordingly.
Foreseeing the possibilities of another war in Europe in the late 1930s, Cox expanded the scrap metals business by opening yards in: Bedford; Birmingham; London (Brentford, Feltham and Park Royal); Manchester; and Neath (South Wales).
[2] Lacking work, by 1924 he turned his attention to the wreckage of the High Seas Fleet, scuttled at its moorings in the natural harbour of Scapa Flow in Orkney, off the North-east coast of Scotland in late June 1919.
Though initially written off by the British Admiralty as unsalvageable, the recent rises in the price of scrap metal had changed the value of the wrecks to the extent that they would now be profitable to lift, based on Cox's estimates of the quantity of high quality Krupp steel armour alone, before taking into account non-ferrous salvage.
The two heavy ships were both accessible from the surface; Seydlitz was often mistaken for a small island as her port flank stuck perhaps six metres out of the water, and Hindenburg was upright with her decks awash.
This was ultimately to prove impractical, as several attempts to lift the Hindenburg ended in failure, due to the hulk's instability and the likelihood of its capsizing whilst being pumped out, as it was sitting on rock and not shingle as had been first supposed.
His team was composed of local labour supporting a core of hired divers and skilled salvage men from all over Scotland; after some practice they were raising a destroyer every four to six weeks, with the fastest lift being accomplished in just four days.
Heartened by this, Cox bought the rights to the remainder of the sunken fleet, and proceeded to lift the battlecruiser SMS Moltke which was upside down in shallow water with her keel at the surface at low tide.
[3] In some cases where the hulls themselves could not be made close enough to air-tight, pontoons were used, similarly being filled with air,[3] and ballast was sunk alongside the sunken ships and then secured to them to counterbalance them for lifting.
The major slump in the price of scrap during 1924 was only really reversed by 1937, in time for his successors Alloa Shipbreaking to capitalise on their investment (the hull of the SMS Friedrich der Grosse alone was valued at £130,000 following salvage that year).
His yard at Lyness on the Orkney Island of Hoy employed 200 workers at the peak of his business, and he was noted for granting holidays with pay during times of financial hardship.