[TowerTalk] Locating Buried Feedline

[Phil Camera]

I'm getting ready to trench in a cable line to a new tower, and before
I do, I'd like to mark where the existing cables are buried,  particularly
near the shack where they all come together.
 
Any ideas what the most reliable/cheapest way to do this is?  Obviously, I will be digging by hand when I get in the "crossfire" of existing cables, but I know that you can do a lot of damage with an errant spade in just one swing.


Go to Home Depot and buy a bunch of those utility marking flags and stick them into the ground at some spacing along the run of the existing cables. 
Or, if the ground is too hard, buy some of that ground marking spray paint and paint little lines over the cables.  

This way when you come towards the line of flags or the paint lines, you'll know when to be careful.

Now if you're not sure where the run of cable is, go get out the map that shows the locations of the cable and the dimensions to nearby objects, which you surely made when you buried the cables way back when.

Am I missing something here?   Phil  KB9CRY