What is the purpose of Poppa-San?

The Poppa-san navigated the men around land mines.

And like the time we enlisted an old poppa-san to guide us through the mine fields out on the Batangan Peninsula. The old guy walked with a limp, slow and stooped over, but he knew where the safe spots were and where you had to be careful and where even if you were careful you could end up like popcorn.