This is way back in my memory but I am sure the Egyptians had made canals between the Red Sea and the Nile.
The ancient Ptolemy’s thought about a Suez canal but thought the differences in sea level between the Mediterranean and Red Sea was greater than it actually was.
You’re right. They dug canals to connect the Red Sea with the Nile River. The ancient canal turned west where the modern one goes north. Eventually, it silted up and goods arriving from the Red Sea had to be portaged to the Nile or the Mediterranean.
Captain Nemo and his NAUTALIS found an underwater-underground tunnel from the Suez to the Med.