What Dummer designed in 1690 was meant to be one dock. The King asked for it to be larger, suitable for first-rate ships of the line. The Navy demanded a basin to protect the dock entrance. By July 1692 the Admiralty had resolved that a full Royal Navy Dockyard should rise around the dock, with storehouses, officers' quarters, and all the apparatus of warship maintenance. Dummer treated efficiency as an architectural principle. He grouped the buildings logically around a central quadrangular Great Storehouse, separated the forge from anything flammable, and built a 'double' rope-house that combined the previously separate tasks of spinning and laying. On the high ground overlooking the yard, he raised thirteen three-storey houses for senior officers in the first known palace-front terrace in England. One end fragment of that terrace, dating from 1692, still stands. It is the earliest surviving building in any Royal Dockyard.

In the 1760s, Devonport, then still called Plymouth Dock, underwent what historians call the Great Rebuilding. Five slipways, four dry docks, and a basin took shape in a configuration still recognisable today. Slip No. 1, built in 1774 and covered with an 1814 timber superstructure, is a rare survival of its type: only three such timber slip covers remain in Britain, and two of them are at Devonport. The 19th century brought a harder problem. Wooden hulls were giving way to iron, sail to steam, and any dockyard that couldn't keep up would be closed. In 1864 a separate steam yard opened at Keyham, north of the original site, connected to it by a tunnel. The Quadrangle, Keyham's vast integrated steam factory with architectural detailing by Sir Charles Barry, is Grade I listed and still works: English Heritage calls it 'one of the most remarkable engineering buildings in the country.'

The Second World War devastated Devonport. By the end of 1942, 85 percent of the South Yard's buildings had been damaged or destroyed. The Officers' Terrace, the storehouses, the sail lofts, all reduced to rubble. The yard worked on through it. In 1993 Devonport was designated the Royal Navy's only nuclear refit base, and Dry Docks 9 and 10 were strengthened to take the Vanguard-class ballistic missile submarines that carry Britain's nuclear deterrent. Today FOST, the Fleet Operational Standards and Training organisation that drives every Royal Navy ship to certification, is based here. So is the Royal Marines' Amphibious Centre of Excellence at RM Tamar, opened in 2013. Devonport became the sole base for the Type 23 frigate fleet when HMS Lancaster retired in December 2025. The future Type 26 frigates will all be based here too.

There is a less comfortable inheritance. Thirteen out-of-service nuclear submarines were stored at Devonport in 2018, awaiting decommissioning that the Ministry of Defence had repeatedly put off because of cost. In 2019 the National Audit Office reported the cost of laid-up storage across all UK nuclear submarines had reached £500 million, with a total liability of £7.5 billion. Devonport itself has had nuclear leaks: ten litres of coolant in 2002, ten litres of reactor-circuit cleaning water from HMS Victorious in 2005, up to 280 litres of likely tritium-contaminated water from a burst hose in 2008. The submarine refit base was placed in special measures by the Office for Nuclear Regulation in 2013. Babcock International, who acquired the dockyard operator DML in 2007 (the management contract having passed to DML in 1987), began a ten-year infrastructure refurbishment programme in 2022, upgrading the nuclear-licensed docks around No. 5 Basin.

Sailors and marines still call the place Guzz. Nobody quite agrees why. One theory traces it to *guzzle*, an affectionate nod to the West Country tradition of cream teas. Another suggests it came from the Hindi word *guz*, meaning a yard of 36 inches, picked up by Victorian sailors who shortened 'the dockyard' to 'the yard' and then to the Hindi cognate. The radio-callsign theory has been disproved. A sailor born and bred in Devonport was once a 'tiddy oggy,' from the naval slang for a Cornish pasty. The cheering shout 'Oggy Oggy Oggy,' picked up by football crowds and revivalist preachers, started at the navy's field gun competition, used by spectators to cheer on the Devonport team. Charles Causley, the Cornish poet, mentions Guz in his 1951 poem 'Song of the Dying Gunner A.A.1.' The name persists where the gunner did not.