The Panama Canal consists of three sets of locks and a large lake in the middle. The purpose of the locks are to first raise the ship up to the level of the lake – about 85 feet above sea level – and then lower the ship back down to sea level. This time-lapse video shows NOAA Ship Okeanos Explorer going through the first two sets of locks. By the end of the video, the ship has been lifted all the way up to the lake level.