Something to consider

[steve in so az]

Over my 30 year detecting career I have kept records of a lot of places , particularly the hot spots. Then every few years I have gone back to them and dug yet more stuff. It's really hard to believe it when I pull up a Merc or even a Walking half dollar from a yard that I "covered completely" years back.

This has happened a bunch of times and I believe that 1. if one keeps on detecting then they should become a better operator and improve their techniques and 2. as the machines improve they should help you find more.
So maybe think about keeping records and hitting the places another day. If you dont then someone else might, Steve in so az