I just finished my first pond. I recently bought a used skid steer with a backhoe attachment. Spent about $9000. Used and older, but a starting point anyway.
My soil is clay with small rocks.
My pond is in the shape of a triangle, with the sides about 100ft each. actually the work area is allot bigger, but I hope it is that size when it gets full. We will see.
I only went about 6 feet deep. I wanted to make it so animals could walk down the slope to drink and get back out.
I spent about 30 hours total.
If you have never used anything but a shovel, The amount of work you can do is incredible.
I will try to take a few pics tomorrow.
Its been raining for a couple days and the water is about two feet deep.