The most storied of the Cadmuses was built in 1818 in New York. She was a packet ship - a working transatlantic vessel sailing the New York-to-Havre route in regular service, the trans-oceanic equivalent of a scheduled train. In 1824 she carried General Lafayette to New York at the invitation of the US Congress, the start of the old French aristocrat's triumphal year-long American tour, where every town between Boston and New Orleans turned out to see the last surviving major general of the Continental Army. From 1827 Cadmus reinvented herself as a whaler out of Sag Harbor, New York, and made seventeen complete whaling voyages, bringing in oil and whalebone worth a total of $359,000 - a fortune at the time. In 1849 a new owner sailed her around Cape Horn to California for the Gold Rush; her crew abandoned her in San Francisco Bay, where she became a leaking storehouse and was finally buried under landfill. Her bones lie under the city somewhere now.

The 1813 Cadmus was launched at Sunderland and traded with the East Indies under license from the British East India Company until 1827. She then made two voyages as a whaler in the British southern whale fishery before being lost in 1835. A 1816 Cadmus, built at Medford, Massachusetts, sailed five complete whaling voyages - one out of Boston, four out of Fairhaven - before wrecking on an uncharted atoll in the Tuamotu Archipelago in 1842. A 1836 schooner-rigged Cadmus, built at Essex, Massachusetts, was bought by Captain Samuel Soper of Marblehead in 1844 and made six whaling voyages before being withdrawn in 1852. Read together, this is American whaling's whole arc - the boom decades when New England men chased sperm whales across all four oceans for the oil that lit American homes, and the slow collapse when petroleum from Pennsylvania made the trade unprofitable.

SS Cadmus, the 1911 cargo steamer, is the one tied to this North Sea location. Built at West Hartlepool for John Gaff & Co. of Glasgow and Sydney, she was bought in 1915 by Christian Salvesen & Co. of Leith and armed with a twelve-pounder gun on her poop deck for the war. On 18 October 1917 she was running from Dunkirk to Blyth carrying 900 tons of spent cartridge cases from British 18-pounder field guns - sent home for recycling, brass being scarce. A German U-boat torpedoed and sank her in the North Sea, twenty nautical miles south by east of Flamborough Head. All twenty-two of her crew survived. In March 1918 the Ministry of Shipping paid Christian Salvesen £83,000 in compensation for the loss. The wreck of those brass cartridge cases lies somewhere beneath this waypoint.

The last Cadmus in the record was a Danish-built motor ship of 1926, launched by Kjobenhavns Flydedok & Skibsvaerft in Copenhagen and owned by L. Harboe Jensen & Co of Oslo. She was chartered to the United Fruit Company. On 1 July 1942, sailing from Tela, Honduras to Galveston with a cargo of bananas, a U-boat torpedoed her in the Gulf of Mexico. Two of her crew were killed and several injured. Twenty survivors took to two boats and rowed for five days before landing near Texpan, Mexico. Two ships named for a Greek hero, sunk by the same nation's submarines in the same two world wars, twenty-five years apart - on opposite sides of the Atlantic. Cadmus, the man, would have understood the symmetry. He spent his old age, the myths say, as a serpent. Pattern was in his nature.