[QUOTE=Topsail;131911] These physics can be understood by an average ordinary seaman or by a Chief (again to humor you), but in reality it is more complicated than that.
p.s. Chief, please have a look to the attached pdf file from p.10 to p.13 and take a special attention to fig. 20,21,22,23 & 24. There is also some videos on the web describing that phenomenon.
Before you get too lightheaded, review your links. In no place does it state that there is a region of what airplane drivers call a “region of reversed command.”
Yes, there is a low pressure area on one side between the hull and the thruster discharge, but as the document, and several other scholarly tomes on the subject clearly state, the location and degree of low and high pressure near the tunnel are responsible for the loss of effectivity as water moves across the opening but have no effect on the direction of thrust. If your link is the best you can do, you have failed completely. Trying to smokescreen the issue with pivot point diagrams and propeller thrust vectors only shows that you cannot provide any citation or description of the physics that will confirm your fictitious statement that at 4 knots a bow tunnel thruster will move the bow opposite the desired direction of movement.
There are several studies available on the subject that, if such a phenomenon existed, would have stated so and described the physics and mathematical model to prove it. When you get off your pedestal, review the literature, you found one that shows you are wrong, find a few more.
Like the yachtie wrote … “pushing on one side and sucking on the other” moves the bow the same direction … in my world anyway.