Europeans developed the economic system of mercantilism and needed reserves of gold and silver.
Shipping technology around the coast of Europe improved immensely, driven by the reality that shipping in ships prior to rail land transport was then hugely cheaper than land transport. Thousands of ships were plying their trade along the European coastline, and innovations in rigging, hull design, navigation, armaments, and reserves of gold and silver were happening all the time.
An increasing population forcced Europeans to look for new lands to colonize.
European powers like Holland, England and France needed spce for their growing population and started to look for new maritime routes and new lands to colonize and send their people to stablish there.