A few years ago we rented a boat to travel the Midi canal in France from Port Cassafrieres to Homps and had the pleasure of traveling some of the aqueducts. Amazing experience.
We've done the aqueduct in Wales. One of the reasons we moved on from sailing to the dark side.
There is barely 6" of water on either side of a 70' long narrowboat in aqueducts, tunnels, under bridges, and in locks.
Highly recommended. Not all that expensive. But I surely dread the whole ordeal of airline travel in this day and age of security and downsized seating.