A phenomena that is attendant to the rotation of a screw-type propeller in a fluid: Propeller Walking is a force, perpendicular, and along the horizontal plane, to the propellers axle. The direction of that yawing force in the direction of motion if the bottom tips of the blades were to enjoy the same type traction as those of a road wheel. For example: looking forward, a right-hand (clock-wise) turning propeller will 'walk' to the right; if left-handed (anti-clock-wise), the propeller would 'walk' to the left.
A single-screwed submarine with a right-hand turning propeller will (at the propeller disc) produce a yaw to the right when going ahead -- that force, working through the vessels c.g. will produce a swing of the vessel to the left and vice versa.
The walking effect is mitigated a bit by a shroud (Kort nozzle for example), and entirely by a properly designed pump-jet.
I'm asking you if you see much walking effect on your VANGUARD, as that is an indication of improper stator-rotor matching. I'm trying to gather some empirical data on the design as it stands today. I have dope on the prototype I built, but additional observation, from disinterested parties such as yourself, would help me refine cause and effect of the current arrangement.
David