Do-It-Ourselves Kid's Water Wheelchair
In this case, the wheels are 22" rather than adult 24", 25", 26". One variation is the design of the footplate and caster supports. I think this is a superior configuration for people with short legs such as children, polio survivors, SCI injured very young, double amputees, etc.
Thank you to the Chisholm family for both providing these photos and improving the footplate design.
Footplate Modification for People with Shorter Legs
Shorter or No Legs
The configuration on the left uses two continues pieces to form the footplate and is geometrically stronger and easier to build than the one on the right. The casters are more likely to be level and stay level over time.