How did Dias and da Gama get round Africa to India?

They got round Africa by leaving the coast behind. In February 1488 Bartolomeu Dias became the first European navigator to round the southern tip of Africa, and he showed that the best way south was diagonally southwest, out in the open ocean, well west of the African coast. Historians still debate whether a storm blew his two small caravels offshore or whether he was deliberately looking for better winds. Either way the ships traced a broad arc around the tip of Africa. Vasco da Gama later used Dias's discoveries to link Europe and Asia by an ocean route.

Dias did not get much for it. His crew was restless and urged him to turn around, with supplies low and the ships battered, and when he returned, his reception at court was muted: no official proclamations and little recognition. Almost every record of the voyage was lost in the 1755 Lisbon earthquake and tsunami.

Da Gama's first voyage, in 1497 to 1499, was the first to link Europe and Asia by an ocean route round the southern tip of Africa, though he was not the first Portuguese to round the Cape. In Malindi his crew hired a Gujarati pilot who used his knowledge of the monsoon winds to guide them across the Indian Ocean to Kozhikode on India's southwest coast. The cost was high: only 55 of the 148 men survived the trip.

The Portuguese were not simply sailing into an empty sea. Near modern Kenya the expedition resorted to piracy, looting Arab merchant ships that were generally unarmed. A new sea route, and a new set of conflicts, had begun.