You might look into renting a professional leveling system. The self leveling models with a audible sensor will save you a bunch of time.
When I prepped the site for my metal barn I bought a cheap level and tripod from HF. It was bright enough to work on a cloudy day and served the purpose but man did I spend a ton of time with it. Every time I moved it I had to relevel before I could do any checking. Of course a lot of that time was working and tamping material then checking then working some more. At the end of the day my Son In Law came over with a Bosch unit from his work to check behind me. It took all of 30 minutes for him to set up and check all of the footer surfaces. BUT I was within 3/4" everywhere using the cheap level. The building design allowed for them to compensate for up to 3" so I was golden.
Thank you. With my civil eng major (non-grad, married and quit college. Doh!), from decades ago I am pretty good with my old- school transit. But lost with today's tech. I think that I might break out my transit and 'shoot it', old school. It's a big shop that I'm working on. So distance is needed with a transit. I think it will work.
With modern tech, a lazer seemed, to me, to be logical. We didn't have that (lazers) so much in the 70s and 80s. As in, Zero.
Shooting for cheap and acurate without too much manpower. A water level is simple, but only as acurate as the person viewing it.
Thanks to all.
Eric