The first time I saw the Panama Canal, it was on a half-day transit trip on a tourism ferry. I enjoyed the tour that time. But because Barbara's arrival date and visit duration precluded taking the same tour again, we improvised and saw the canal from two different viewpoints . On Day 1 we explored the canal up-close on a small launch that included an eco-tour of Lake Gatun and some of the small islands therein. We kayaked to a waterfall, lunched on a river barge, visited monkeys, and petted iquanas, crocodiles and boa constrictors.
On Day 2, we visited the Miraflores Locks, watched large ships enter and transit through them, and toured the 4-floor Canal Museum. For me, seeing the operation from above and afar was much more informative than being on one of the boats transiting through the locks. This time I could see the forest, so to speak. The last time I was too close for an overview.
Although I'm still unclear regarding much of the physics and technology of the canal, I did understand that when passing from the Pacific to the Atlantic (Carribean), the ships are elevated a height of 28 meters, in two stages, and then lowered back to sea level on the other side. Water utilized to raise the vehicles, currently is lost into the seas.
The canal expansion project, which includes construction of new, larger locks, will have a system to recycle the water utilized for this process.