He captained two important expeditions (in 1445 and 1446), which expanded the limit of the Portuguese discovery of the West African coast, probably as far as the northern borderlands of modern Guinea-Bissau.
Two of the ships were outfitted by João Gonçalves Zarco, donatary of Funchal, who appointed his nephew, Álvaro Fernandes, created by Prince Henry, to captain one of them.
[2][3] According to 15th-century chronicler Gomes Eanes de Zurara, Álvaro Fernandes went out alone, personally instructed by Prince Henry to avoid any raids, and aim straight for Guinea for the glory of exploration alone.
[5] Álvaro Fernandes continued sailing down the Grande Côte of Senegal until Cape Verde, the farthest point reached by Dinis Dias.
[6] Fernandes is said to have left his marker on the island by carving Prince Henry the Navigator's knightly motto, Talent de bien faire ("Hunger for good deeds") on a tree trunk.
The first encounter went smoothly enough—gestures were exchanged expressing peaceful intentions, and several of the natives were invited aboard, and given food and drink by the Portuguese, before setting back in their canoes and returning to the mainland.
They came upon a small hunting party of four natives (possibly Serer) in the vicinity, and tried to capture them by surprise, but the startled hunters managed to escape and outrun the Portuguese.
The next Portuguese ships to arrive in the area—the large slaving fleet of Lançarote de Freitas a few months later—would be greeted by a hail of arrows and poisoned darts, and forced away.
[13] Fernandes headed straight to his last point (Cabo dos Matos), and landed a little exploring party, but finding nobody, re-embarked and continued sailing on.
Álvaro Fernandes killed what he believed was the native chieftain at the beginning of the encounter, prompting the rest of the local warriors to briefly halt the fight.
The caravel resumed sail, and continued "for a certain distance", until they reached a large river, which is recorded in the chronicles as "Rio Tabite" (location uncertain, see below).
Although probably aware of the fate of Nuno Tristão on a similar river venture, Alvaro Fernandes nonetheless decided to set a launch to explore upriver.
But given Fernandes's ill condition and still shaken by their earlier near-escape, the decision was made to quit the area and set sail back to Portugal.
On the way home, Fernandes stopped by Arguin island and a nearby cape in the bay, where they negotiated the purchase of a black slave-woman from some Berber traders.
Upon arrival in Portugal, Álvaro Fernandes was amply rewarded by Prince Henry the Navigator who offered him 100 dubloons, and regent Peter of Coimbra, who gave him another 100, for having sailed further than any other Portuguese captain thus far.
[26] In particular, it is highly unlikely he would have sailed past the huge Geba River and the many Bissagos Islands and other notable promontories and landmarks without exploring them or making the least mention of them.
[29] (It contrasts sharply with the fate of Nuno Tristão and his crew in the Diombos River, where a score of men fell dead quickly from Niominka poison.