I wanted to say Kortz nozzle
Missus the slow speed manoverability of a jet is stunning, the downside of them is that they are not as fuel efficient as a prop and they usually run from an inboard.
Hugh. the mall jet boat things tend to have a different control system from proper rib type Jets. The jet has two controls a forward and reverse and steering. The motor has one control accelerator. You may have an optional gearbox but it isn't needed
You set the revs on a motor and then don't really need to adjust it after that as you control the momentum via the forward reverse control. when you get used to this it's very assuring
Now don't all go posting links to the outboard jet drive