This is the case only when the blades begin to turn and when the boat is standing still. As soon as the boat is moving forward, the angle of attack is reducing. The faster the boat goes, the more reduction in that angle.
The article describes how the wing works and you can see that, when stationary, the pitch equals the angle of attack and this is far too great for a prop blade to operate properly. This, of course, is why big pitches don't work well at low speed.
Now, this bit is only what I feel must be happening at low speeds and it is only based on deduction. The water at the front of the blade will be largely turbulent and this will be a low pressure area. The water at the back of the blade will be impinging on the blade face and be diverted back producing increased pressure on the blade so providing some thrust. The water captured within the blade area will probably be thrown outward under centrifugal force and so behave as a centrifugal fan. These forces combined are sufficient to produce forward motion. This begins to reduce the angle of attack so all these factors begin to reduce and the efficiency improves and off we go gaining speed.
If the prop has less pitch to begin with, it is a step ahead.
This is why the Torqueshift works so well and also why I am a genuine convert.
Edit...JK can I ask a favour? Are you able to increase the time allowed to compose replies because I am often logged off the system before I am finished. I have to remember to cut the text and then go through a loop to repost before the next timeout.