DSK wrote:

.... At full speed, the prop stream does increase rudder
effectiveness but I'd say that it's not "significant."


otnmbrd wrote:

Would disagree. Prop wash is a very important contributor to rudder
effectiveness at all speeds .... put a ship's engine on "stop" ....
trust me, your effectiveness decreases rapidly.


How about when letting the prop freewheel from full speed?


That does not help. A freewheeeling prop usually takes more energy from
the wake than a stopped prop when the vessel is moving fast.

Cheers