Keith #9 I went through the canal in 1970 on an Ellerman and Wilson ship (Cicero) I remember it being a short canal and not a very long transit compared with the likes of Suez and the panama.
Tony #10 It looked scary as you looked up also , there were some very solid looking cliffs towering above and very close to the ship I have no Idea what the captain and navigators thought about it but there was not a lot of room to make a mistake and I have never read about accidents on that canal.