Two giant ships move through the Panama Canal's two parallel channels at the Miraflores locks, heading toward the Pacific Ocean.
The orange and white Bow Summer is a tanker. The deck of the Ever Dynamic is stacked high with burgundy and blue shipping containers. More boats like these are backed up in both the Pacific and the Atlantic waiting to enter the narrow waterway.
Global trade has grown dramatically, but the Panama Canal — one of the most vital transit routes — hasn't changed its basic structure since it opened in 1914.
But that is about to change.