[1][2][3][4] Washington joined the Royal Navy in May 1812, and served aboard HMS Junon with Sir George Cockburn's fleet in Chesapeake Bay, seeing much action in the War of 1812.

He obtained permission to return to England by his own route, and took the track later followed by Darwin riding over the Andes to Mendoza and then across the pampas to Buenos Aires.

[7] From 1830 to 1833, he was flag lieutenant to Sir John Beresford, Commander-in-Chief, The Nore, and on 14 August 1833, Washington was promoted to the rank of commander.

[8] In 1838 he published an account of Mohammedu-Siseï, a Mandingo from The Gambia, who had been enslaved, freed, and served as a soldier in the West Indian Regiment.

He took over the North Sea survey after the death of William Hewett, whose ship HMS Fairy was lost with all hands in a storm in 1840.

In January 1842, he was temporarily lent to the yacht HMS Black Eagle, which was appointed to bring Frederick William IV of Prussia to England.

An important part of Washington's work in the North Sea was confirming Hewett's observation of a point with neither rise nor fall of the tide.

Washington was asked to investigate the disaster, and the Report on the loss of life, and damage caused to fishing boats on the East Coast of Scotland, in the gale of 19th August 1848 was published the following year.

At Wick as the storm increased towards midnight on 18 August, many of the hundreds of fishing boats in the bay ran for the harbour and got in safely around high water (about 01:30).

By the time the storm was at its worst, between 3 and 5 o'clock in the morning of the 19th, the water had fallen to half tide, and it was impossible to enter the harbour safely.

A committee was set up to judge the entries, with Washington as chairman, and produced a report the following year, which included illustrations of the most promising designs, and also a chart marking the wrecks round the coasts of Britain and Ireland in 1850.

[4] In 1853, having to visit Denmark, Sweden, and Russia to settle some matters as to an establishment of lifeboats, he was directed by Sir James Graham, then First Lord of the Admiralty, to collect what information he could as to the state of the Russian Baltic Fleet and the defences of Kronstadt, Reval, and Sveaborg.

His term as hydrographer began in wartime, and the first priority, already underway while he was Beaufort's assistant, was the supply of charts, particularly to the French Navy.

Many at the time believed that has illness and death were the result of overwork and worry about accusations in the press that failings in the hydrographic office had led to the loss of HMS Orpheus in New Zealand.[1][6]: 286–287 .

His funeral in Le Havre, on 19 September was attended by French civil, and military representatives as well as by British seamen and townspeople.