After leaving the Antarctic, Dumont d'Urville sailed north to Hobart, visiting the Auckland Islands before moving on to New Zealand. He sailed up the east coast of the South Island, stopping first in the Port of Otago, then Akaroa (8 April 1840), and finally the Bay of Islands, where the Treaty of Waitangi had been signed just months earlier. The explorers returned to France by way of New Guinea, Torres Strait and the Indian Ocean.
In April of 1840 the Astrolabe made to enter Akaroa harbour to replenish their food and water supplies. The ship was becalmed at the entrance to Akaroa harbour for 5 hours. The crew held fears for their safety and that of the ship, when the wind dropped and the current nearly swept them onto rocks. Fortunately, the wind picked up just in time and their own launch and a boat from port towed them safely into the harbour. Due to the light winds the Zélée did not enter the harbour until the next day.
Dumont d'Urville described the harbour as follows:
"The land round the bay is mountainous and very broken. The best anchorage is situated near the eastern shore, opposite a very narrow little valley in which there are a few native huts. We only found two whaling vessels [one French, one American] in this splendid harbour which could hold more than fifty."
(Wright, 1955, p. 43)
There were also 3 French whaling vessels in Peraki a few miles west of Akaroa. The French government was thinking of settling in Akaroa, and indeed 57 French settlers did arrive at Akaroa in August 1840. However Dumont d'Urville's recommendation, due to its rugged, mountainous terrain, was that "..without doubt Akaroa Bay would be a very poor choice for a first settlement" (Rosenman, 1987, p. 532).
They were set to leave Akaroa on 12 April, but due to unfavourable wind and rain they remained until 17 April. After leaving Akaroa they charted the east coast of South Island as far as Cape Campbell, the northernmost point. This was the end of their hydrographic work in New Zealand, having charted the east coast of the North Island in their previous voyage in 1827.