Conversation so far:
When did Ferdinand Magellan depart and cross the Atlantic?
Ferdinand Magellan's fleet left Spain on 20 September 1519, sailing west across the Atlantic toward South America.
Did Ferdinand Magellan's fleet have problems before leaving Spain in 1519?
After having his proposed expeditions to the Spice Islands repeatedly rejected by King Manuel of Portugal, Ferdinand Magellan turned to Charles I, the young King of Spain.

Question: why did they need to be resupplied?
Self-contained rewrite: Why did Ferdinand Magellan's fleet need to be resupplied?