It depends on what you want to measure:
You could want to know:
the area,
the depth,
the volume of water,
surface temperature,
temperature at depth,
salinity,
pollution level,
animal life,
etc
Miles
I don’t know
Measuring Lake Erie from the Canadian side would probably be in kilometers. On the US side would probably be in miles.
You would use meters or feet to measure the depth of Lake Michigan.
Meters
Lake Powell is approximetly 100 miles long depending on how how you measure it.
Yep. you can measure anything in feet. but for some it might take a while.
Meters
gallons
kilometers
typically, acresMy VersionI measure a lake in surface area, Square Miles in my case, and Ice thickness for safety. As you can see my measurement is for my uses.You may measure the amount of water, the depth of the water, The cleanliness of the water, the height of the lake above sea level or dozens of other ways depending on what you need to know.
0.281 km.