I've had one for 2 years now, and you need at leat 1-2ft of water to use the miragedrive... in really shallow water you can kinda do short little half burst kicks to get through, but it wouldn't be practical to go a long distance in real shallow water.
I agree that the PA is totally at home in very shallow water. I, too, use the partial pedal strokes in these situations. It's important to understand that you want to use very small pedal movements. If I think of a full pedal stroke as one pedal moving from full forward to full back, or vice versa, then a half stroke would occur when the pedals are even with each other in the middle of the stroke. I find it is natural to want to bring the pedals to an even position when trying to short pedal. However, when the pedals are even in mid stroke the fins are actually at their fully extended position under the boat. You want to just flutter the pedals, using a quarter stroke at most, to keep the fins close to the hull, but still provide some propulsion. It's surprising how much you can generate by positioning the pedals at opposite extremes and just barely moving your feet to flutter the fins. I've learned all this the hard way! As noted in other message threads, bent masts can be straightened.