Quote: I had expected them to be a lot wider than they are, the gates are just like the Erie Canal lock near where I live, but more massive. There are two locks, side by side, and when we were there a cruise ship was in one and a freighter and a couple tugs in the other

Yes an amazing feat of engineering.
when Jimmy Carter gave them back to Panama the Panamanian government couldn't maintain them and the heart broken Chinese government took over the canals to help the Panamanians government, of course for a reasonable fee.
It's nice to have a considerate country like China in control of one of Americas strategic waterways and by a country that loves us.
All of our Aircraft Carriers and other military ships were built from the ground up to pass through the canals of Panama And the Suez.
Ever wonder why the Carriers are wide on top and trimmed (skinny) to the waterline.