Complex sentence: England, France, and the Dutch Republic enviously watched the Spanish and Portuguese wealth grow and allied themselves with pirates such as Henry Mainwaring and Alexandre Exquemelin who could explore the convoys leaving America as prevailing winds and currents made the transport of heavy metals slow and predictable.
Split into simpler sentences: England, France, and the Dutch Republic enviously watched the Spanish and Portuguese wealth grow and allied themselves with pirates such as Henry Mainwaring and Alexandre Exquemelin. They could explore the convoys leaving America because prevailing winds and currents made the transport of heavy metals slow and predictable.