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How to Gauge Water Depth in a Lake

The act of measuring the depth of a body of water is a practice as old as maritime navigation itself, and has many important applications. Perhaps you are trying to determine the length of piling required to safely support a dock. You may have dropped something in the lake and want to know how far down you will have to dive in order to retrieve it. Whatever the case, gauging the water depth of a lake requires very little in the way of preparation or materials.

Things You'll Need

Watercraft
500 feet twine
Heavy metal washer
Pen
Tape measure

Instructions

- 1
  Navigate your watercraft to the point in the lake whose depth you wish to measure. If you are measuring a point adjacent to the shore, walk to that point on the shoreline.
- 2
  Tie one end of the twine securely to the washer.
- 3
  Drop the washer into the lake, and let out the twine until you feel the line go slack.
- 4
  Retrieve the slack of the line to the point where it goes taut. Reach down to the surface of the water and pinch the twine with your fingers right where it is touching the water.
- 5
  Pull the twine back into the boat, continuing to hold it with your fingers at the point where it was touching the surface of the water. Mark that point with a pen and pull the rest of the line out of the water.
- 6
  Measure the distance from the point of the pen mark to the washer with the tape measure, ensuring that the twine is taut when doing so. The distance will be equal to the depth of the lake at the point of measurement.

Nature