His writings talk of days lasting three months, and of a vast southern continent, the Terra Australis, and the Jave la Grande, which he claims to have seen south of Southeast Asia, possibly suggesting he had approached the Arctic (by North America), Australia, and Antarctica.

In 1531, John III of Portugal attempted to repatriate the defector pilot because of his high qualifications and for his vast and possible classified knowledge.

[citation needed] The crew of 200, including prisoners and a few women, spent a harsh winter on the shores of the St. Lawrence River, hit by scurvy and losing a quarter of the colonists before sailing back to France.

[5] In late 1544, Alfonse left La Rochelle with a small fleet and disrupted Basque shipping, while the treaty of Crépy had just been signed between France and Spain.

In them he describes the various places and peoples he and others have seen, many of them for the first time in print (such as Gaspé, the Beothuk, Saint-Pierre Island, the jewels of Madagascar, a continent south of Java) and provides navigational instructions on how to get there.