A muddle 19:42 Jan 25
As Simon rightly says, the “Cabo del Boxeador” is mentioned in some old Spanish histories as a cape in the Philippines. I’m not sure what it’s now called, but the sources suggest that it is in the north of the islands.
However, I don’t think this can be what the text refers to. It is talking about Portuguese discoveries. The Philippines were (officially) discovered in 1521 by Magellan. He was Portuguese, but he was working for Charles V, and he claimed the islands for Spain. It was not a Portuguese discovery (even though some Portuguese had probably reached the Philippines before this). So it is not likely that João de Barros, the great chronicler of the Portuguese discoveries, was referring to the Philippines. On the contrary, the text says that the Infante who sent the captains to try to sail round this cape did not want the Spanish to find out what the Portuguese had discovered.
This reference to the “Infante” (evidently Portuguese) is the most important clue. In the context of voyages of discovery, this must surely refer to the Infante Dom Henrique de Avis, known in English as Henry the Navigator. And this must mean that the cape referred to is Cape Bojador, in west Africa. | 
The translation workplace 
peer agreement (net): +3
