How Ships Are Raised and Lowered in the Panama Canal

Ships transit the Panama Canal via a system of six locks (three on each side of the continental divide). Each lock is a watertight chamber:

1. Ship enters; gates close behind it.
2. Water is pumped in to raise the ship (or drained to lower it).
3. When water levels equalize, gates open; ship proceeds to next lock.

This engineering marvel has enabled Atlantic–Pacific passage since 1914.