Originally Posted by fj5gtx

Off topic, but I'll bite to demonstrate that sometimes old tech is worth leveraging.

I use a bucket with a nipple low in the side and some tubing. If you hold the tubing up, and put water in the bucket, the water level will rise in the tube to the same height as the water in the bucket. So you put the bucket in the middle and walk around and see where you are at depth wise. Leveraging this physical science fact has be been tracked back as far as the Egyptians. There are a ton of references to it on the internet, and lots of variations. I usually zip tie the tube to a stick of wood, and then mark my high or low spot. People go a little crazy, buying all kinds of stuff to make it marginally better... I'd rather use the $ to fund something I don't have...

I used to just rent a laser level (spinning one) when we dropped in a new building or driveway. The key to getting it right is to first level the silly laser level main unit, usually with a bubble float. Besides high sunlight days causing you grief seeing hte laser, even a small deviation to level will propagate the error and cause you a large deviation if you're doing a large area. If the water deviates from being level over distance, you - well everyone on the planet, has a much larger problem!