It quit raining a couple of hours before dark so I took the Etrac for a depth test to an old country church parking lot with about 5" of gravel under about 2-3" of sod and it had no problem hitting the coins pictured at 9" plus. In auto it ran at 21-23 and would not hit solid on them but in manual at 27 they hit solid and ID decent as well.Yeah the depth thing bothers me to,digging that deep in gravel is tough but worth it.Ray.