Hi Armando,
The twin props on my Dutch Courage tug (model Slipway) are controlled by separate esc’s, although I prefer not to use a mixer, but instead the ‘tank control’ method, whereby the left stick on my transmitter controls the left motor, and the right stick controls the right motor. Although twin rudders are fitted, I rarely use them as the boat is highly manoeuverable with just motor control. In fact, it will easily rotate on the spot.
When turning right, for example, the left stick will be in a forward position, and the right stick will need to be positioned to determine the tightness of the turn – if also forward (but less so than the left stick), the turn will be gentle. If in the neutral position (ie motor off), the turn will be tighter, and if in reverse, the turn will be tighter still.
If one stick is fully forward, and the other fully back, the boat will, as previously mentioned, rotate on the spot.
Dutch Courage has fixed Kort Nozzles, and I’m not sure if the manoeuverability would be the same for boats without these, ie ‘exposed’ props.
Regards, Paul.