Lymington had a long history of smuggling, beginning with the surreptitious transport of wool to the continent in the 17th century to evade high excise taxes.

[5][6] By the age of 12, when his father died, Johnstone was an accomplished mariner and his familiarity with the English Channel and the coastal waters from Cornwall to Suffolk made him a much sought-after maritime pilot.

[5][6] Johnstone began smuggling aged 15, fought against the French in the Napoleonic Wars as a privateer, operated as a British double agent and led teams of divers to plant explosives on enemy shipping and fortifications.

[11] Johnstone managed to escape confinement on each occasion and the 1823 publication The Historical Gallery of Criminal Portraitures, Foreign and Domestic reported: "No prison has yet been found strong enough to hold him.

The operation involved using a submarine to pick up Napoleon from near the shore and then transferring him to a waiting sail boat for onward transport to the United States.