You better bring a grave diggers shovel for that first detector if you want to get to the treasure.
Man that was way before pin pointers and depth estimation days.
I remember using my Garrett DeepseekerADS III in the early 80's. I dug a balled up cigarette pack at elbow deep. That was 15" measuring tip of fingers to elbow.
I've not dug a target that deep since I returned with modern machines. That was about 34 years ago - and Garrett rocked!
I do wish I still had my ADS III, lost along the way in my travels.....
At Max,Xp deus,At pro, At gold, pro pointer, ace 350 bounty hunter. Lesche hand and t handle digging tools, Sask kustom digger, Garrett edge digger and Garrett retriever, Garrett classifier made into
First detector I ever played with was my grandpa's ADS groundhog I believe. Used it to find aluminum arrows after target shooting before archery season in the mid 80s