In Cook's Footsteps: A French Scientific Mission
Jules Dumont d'Urville held deep respect for James Cook, drawing inspiration from the English navigator's cartographic precision.1 D'Urville had first visited New Zealand in 1824 as second-in-command aboard the Coquille.2 Returning three years later as commander of the renamed Astrolabe, he sought to complete the coastline details that Cook had bypassed or observed only from offshore.3 His crew of seventy-nine included naturalists, hydrographers, and official illustrator Louis Auguste de Sainson.4
Beyond its scientific objectives, the expedition carried confidential directives from the French Ministry of Marine to report on strategic locations suitable for trade or penal settlement.5 France, recovering from decades of revolutionary instability and Napoleonic conflict, sought to expand its Pacific influence alongside Great Britain. D'Urville approached his duties as both a naval officer and an educated polymath, studying local Polynesian dialects to better understand regional ethnography and cultural history.6
Charting Te Hoiere and Croisilles Harbour
Sailing along the northern reaches of Te Waipounamu into Tasman Bay, d'Urville identified an opening along the jagged coastline.7 Entering the sheltered inlet, he named it Croisilles Harbour to honour his mother's family, the Demozay de Croisilles.8 D'Urville dispatched soundings boats into the surrounding inlets, discovering deep anchorages bordered by steep, forested hills.
D'Urville guided the Astrolabe further east into the extensive waterway of Te Hoiere / Pelorus Sound.9 Cook had sailed past the sound's outer entrance without venturing inside.10 D'Urville spent days surveying the intricate channels, recording depth soundings and mapping coastal contours.11 The ship's naturalists collected biological specimens, including samples of bull kelp later named Durvillaea antarctica in the commander's honour, while de Sainson sketched views of the surrounding coast.12
The Tradition and Peril of Te Aumiti
Seeking a direct eastern passage into Admiralty Bay to avoid sailing around the northern tip of Rangitoto ki te Tonga, d'Urville investigated a narrow channel separating the island from the mainland.13 Local Māori knew this roaring passage as Te Aumiti, a name linked in oral tradition to Kupe's pet shag Te Kawau-a-Toru, which drowned while testing the violent currents.14 The narrow channel features extreme tidal flows reaching speeds up to eight knots, creating swirling whirlpools over submerged reefs.15
Recognising the severe hazards, d'Urville sent his officers in small boats to probe the channel and measure current speeds during slack water.16 Local Māori warned the French sailors of the dangerous rocks, advising against attempting a passage in a square-rigged vessel.17 Despite these warnings, d'Urville decided to attempt the passage on the morning of 28 January 1827, calculating that favourable winds might carry the corvette through the narrow gap.18
The Daring Passage of French Pass
As the Astrolabe entered Te Aumiti, the wind faltered, leaving the 380-ton corvette at the mercy of a surging eight-knot ebb tide.19 The vessel was dragged sideways into the churning passage, swept uncontrollably toward the jagged reefs flanking the channel. Officers and crew fought desperately at the helm and rigging, attempting to catch any stray breeze to regain steerage.
The tide slammed the Astrolabe twice onto the rocky reef, tearing away portions of its false keel and sending heavy vibrations through the timber hull.20 For fifteen terrifying minutes, the ship lay trapped in the whirlpools before a sudden gust of wind filled the sails, driving the battered vessel off the rocks into the deep, calm waters of Admiralty Bay.21 D'Urville named the channel Passe des Français (French Pass) to commemorate their survival, while his officers named the adjacent landmass D'Urville Island in his honour.22
Cartographic Legacy and Impact
D'Urville's survival at French Pass allowed his team to preserve invaluable scientific records.23 The expedition produced detailed charts of the Marlborough Sounds that significantly improved upon Cook's earlier maps.24 These French charts served as essential navigational references for merchant captains, whalers, and naval commanders navigating Cook Strait for decades.
Upon returning to France, d'Urville published extensive multi-volume accounts of the Astrolabe voyage, featuring de Sainson's lithographs and detailed linguistic comparisons between Polynesian dialects.25 His work established Te Aumiti / French Pass as one of the most famous maritime passages in New Zealand history, leaving a permanent French legacy across the geographic nomenclature of Marlborough.26