Pond Boss Forums INTRO Questions & Observations How to make a water depth indicator?

I need to know with a degree of accuracy what the water height is in my pond both above and below "full". Because the soil here is so full of rocks I never know how deep I can pound in a stake so just numbering a stick and pounding it in won't work. So before I spend alot of time dreaming up ways to do this maybe someone out there has some advice.