[Retric]

The wheel still uses energy from the water source to lift the craft. The real advantage is it takes far less water while looking cool. It’s also tall for a lock.

I think the most efficient system to build and use would be a "bucket" and pulley’s attacked to a counter weight. Granted it would have far less summitry and not look as cool. The main advantage to locks is they scale really well but they use more water.

PS: I can't help but wonder how they counterbalance the buoyancy when one end dips into the water. Those curved tips might help and I can world out the geometry in my head but I think they just brute force it.

[DannoHung]

I don't think any of it dips into the water. It looks like there's a dug out portion for the wheel to turn into.

[Retric]

Thanks, I just noticed that the edges where not wet in the pictures so I think you are correct.