Just as ordered, and quick!
I'm a gardener, not a golfer, and I needed a way to remind me -- and my wife -- where the new power line ran underground from the house to the garage. Something inconspicuous but clear, something durable and inexpensive -- golf ball markers! For only $10 I got a dozen little plastic disks that I made to say "WIRE PRESENT DO NOT DIG." I snipped the short pegs off the back and used epoxy to glue the disks to long galvanized spikes. Then I just inserted them in the garden soil along the path of the power cable. Just like that, an easy, inexpensive, and long-lasting way to avoid big problems.
And I suppose, if you ARE a golfer, these would be great to mark the ball's location on the green!