‘It is easier for an officer to keep men healthy, than for a physician to cure them’, Vice-Admiral Horatio Nelson concluded in 1804. Naval officers and surgeons had expressed such sentiments before, yet the Royal Navy had a patchy record regarding the well-being of its seamen. Life afloat offered few advantages. True, by the early nineteenth century some medical officers contrasted the bracing sea air which filled a sailor's lungs with the foul atmosphere of Britain's industrialising cities, and they spoke highly of the regimented work and discipline imposed by the daily routine of a man-of-war. It was also observed that sailors and marines were paid regularly, even if many squandered their money on foreign shore leave or in the backstreets of Portsmouth, and, further, that they were spared many of the responsibilities which weighed upon men in civil life. But for the most part seamen had to contend with hardships which endangered their lives or destroyed their constitutions. In 1799 the eminent naval physician, Sir Gilbert Blane, asked why sailors appeared to age prematurely. After ten years at sea their bodies were worn out and the contrast with the civilian population was plain to see. Invaliding seamen no longer fit for duty was a common chore for medical officers: for hernia alone, the navy invalided on average 3,714 men annually between 1744 and 1800 – one in seven of the entire force. Vast numbers were less fortunate. Throughout the seventeenth and eighteenth centuries naval men perished in their thousands in warfare and from exposure to diseases which were a mystery to medical science.

Warships, of course, were dangerous places and accidents abounded. Men fell from masts and rigging, or went overboard and drowned. They could be crushed as guns, stores and equipment broke loose in heavy weather. Drunk or sober, they slipped through unguarded hatchways. Boats capsized; wheels smashed arms and faces when spinning out of control in storms; recoils or false discharges during gunnery practice cost arms or legs; and sharks might attack men bathing alongside the vessel.