Panama Canal: The Eighth Wonder of the World1998

R.M. Koster:
The highest elevation at Suez was 50 feet above sea level. Here, it was 330 feet, and that translated into millions and millions of cubic yards of dirt to be removed. At Suez, you had mostly sand. Here, you have rock and, what was worse, mud. The mud was terrible here; The more you dug out, the more slid in.