João de Trasto is the name sometimes given to an obscure (and possibly fictional) Portuguese mariner, who is alleged to have captained the first exploratory expedition dispatched by Prince Henry the Navigator in 1415.
Probably departing from the port of Lagos, the Trasto expedition was forced by foul weather to the part of the Grand Canary island subsequently called Telli.
As the historian R.H. Major writes, after retelling the Trasto story in his 1868 edition, "there is however so much that is manifestly inaccurate in other statements of Diego Gomes respecting the early voyages which he narrates from hearsay, that we cannot be perfectly sure that the date here applied to the earliest expedition is correct.
[5] Some historians have suggested that Diogo Gomes probably meant to refer to D. Fernando de Castro, who is indeed recorded to have led a failed expedition to Gran Canaria for Henry the Navigator in 1424.
[6] Indeed, it seems "Trasto" is a mistranscription in the first (1847) printed edition of Diogo Gomes's letter, that the original manuscript actually read "Crasto" (probably meaning "Castro").