h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Hi,
In the Algarve it is considered that when Columbus was shipwrecked he was rescued by the sailors of Lagos. Lagos was the centre of the Portuguese Discoveries and overseas commerce until the death of Prince Henry the Navigator in 1460
Felipa Perestrella's father was not only a well-known seaman but was given the post of Governor of Madeira.
Christopher often used to hang out at Madeira and it was there in 1486 that he managed to obtain the rutter (route log) of Afonso Sanchez of Cascais, who had been carried too far West by storms and had sighted North America.
Madeira was an excellent place to learn about voyages in the Atlantic, as it was the usual landfall before Europe.

Watermusic

It is well known that Columbus had been passed Portuguese navigational information from one of his relations. The Portuguese were already aware of the Caribbean islands also maps and navigation were considered secret by Portuguese sailors.