Joshua Slocum begins his narrative by detailing the meticulous reconstruction of the antiquated thirty-six-foot sloop Spray in a field in Fairhaven, Massachusetts. Using pasture oak, Georgia pine, and a thousand screw-bolts, he crafts a vessel stout enough to withstand the most violent gales. In April eighteen ninety-five, he weighs anchor from Boston, intent on circumnavigating the globe entirely alone, guided only by a tin clock and his own profound knowledge of the sea.
The voyage across the Atlantic brings early trials, including thick fogs off Sable Island and an encounter with a Spanish bark whose captain exchanges wine and warnings. Slocum describes the psychological shift from the acute pain of initial loneliness to a deep, contemplative solitude. After calling at the Azores and braving a severe gale where a phantom pilot of Columbus's Pinta seemingly takes the wheel, he passes through the Strait of Gibraltar, where British naval officers extend remarkable hospitality.
Leaving Gibraltar, Slocum narrowly escapes Moorish pirates off the coast of Africa by disabling their craft in a squall. He crosses the equator and makes landfall at Pernambuco, Brazil, before heading south into the treacherous waters of the Patagonian coast. Here, a miscalculation strands the Spray on the sands of Uruguay, leading to a narrow escape from shipwreck and an encounter with inquisitive locals.
Entering the Strait of Magellan, Slocum confronts the extreme dangers of the region, including fierce williwaws, treacherous tides, and hostile Fuegian savages. Armed with a bag of carpet-tacks provided by an Austrian captain, he secures his decks at night against barefoot intruders, outwitting the notorious murderer Black Pedro. From Cape Pillar, the Spray plunges into the Pacific, where a tremendous tempest drives her far south toward the Horn, testing the absolute seaworthiness of the vessel in the greatest sea adventure of the voyage.
Surviving the fury of the southern ocean, Slocum makes his way to the historic island of Juan Fernandez, the refuge of Alexander Selkirk. He regales the local islanders with Yankee doughnuts and gathers provisions before setting a course westward across the Pacific. Seventy-two days pass without touching port as the Spray rides the trade-winds to Samoa, where he meets the family of Robert Louis Stevenson and experiences genuine island hospitality.
Continuing through Torres Strait and along the perilous Barrier Reef of Australia, Slocum visits Tasmania and Melbourne before turning his bow toward the Indian Ocean. Stops at the Keeling Cocos Islands and Rodriguez provide peaceful respite before he rounds the Cape of Good Hope. Welcomed warmly in South Africa by figures such as the explorer Henry M. Stanley, Slocum finally completes his historic journey, arriving back in Massachusetts after more than three years at sea.