Notamermaid you’ve got it in one basically laden and unladen weight, water being one of the heaviest things (if water is a thing?) you can carry. So to get through a shallow section, shed as much water as possible, ensure that the boat is stable and crawl with fingers in ears not to hear the hull scrapping on the bed of the river/canal, best done at night so as not to upset your passengers.
Just a technical note although it may be possible to transverse a shallow section if that section includes a lock then you may have a challenge it depends how it is constructed. Oh these engineers there always fiddling with designs.