This article examines the relationship between travel narratives and the construction of knowledge of the New World. It studies how Juan Ladrillero's narrative -a famed pilot who arrived to Chile with Garcia Hurtado de Mendoza- about the journey to the Strait of Magellan, conducted between 1557 and 1559, is rewritten in two official chronicles of the Indies. It underlines the strategies of these texts used to support their authority as bearers of new knowledge. While travelers texts emphasize their place of enunciation and the telling of a unique experience, official chronicles establish hierarchies between "informants" and authorities, organize, decontextualize, summarize or compare and verify information from their sources in order to sanction their accuracy.