water level is built from two tall stakes with markings and
a long line of plastic tubing, filled with colored water.
I used it to level the foundation. Here, I am checking the
level of one of the boards used to form the foundation, inside
the trench dug by the tractor. It doesn't matter how much
the tube travels up and down, because at the two ends the
water will always seek to be level, as long as there are no
air bubbles inside.