Bad vis is also known as normal working conditions means I can't see anything.
Good vis means I can see something.
Great vis means that I can see it before I can touch it.
The best vis was being able to see about 6" (yes, inches) when it let me find and fix the leaking flange on a pipe plug in a few minutes instead of several hours to pull the plug, do the repair and put it back with the lost time to the customer due to the plug leaking down and letting the water through.
The longest vis was something more than 100'. I had no way to measure but the bottom was clear from the surface at a depth of 80'.
I am more interested in what I can see than how far I can see.
Good vis means I can see something.
Great vis means that I can see it before I can touch it.
The best vis was being able to see about 6" (yes, inches) when it let me find and fix the leaking flange on a pipe plug in a few minutes instead of several hours to pull the plug, do the repair and put it back with the lost time to the customer due to the plug leaking down and letting the water through.
The longest vis was something more than 100'. I had no way to measure but the bottom was clear from the surface at a depth of 80'.
I am more interested in what I can see than how far I can see.