How to find hidden metal participation in land.?

There is a property dispute in my family. Before, when the land was distributed among my relatives, put metal stakes into the ground to mark property lines. In the course of 50 years or less, the earth has moved around, and the game probably have sunk into the ground (which is around a lake). We know the general area are, but we can not find the game. We have tried a metal detector, but do not know the depth in the search. Is there any way to locate the metal game? Thanks

Yes pay a surveyor to find them. Or go to their local council and seek their plot. Plot should be in writing also. Ask your neighbors next door, is your game too.

Depth Test Tesoro Silver Sabre Umax metal detector