Metal Detectors

I need input on metal detectors what brand is a good one , how good do they really work. I am going to try to find some treasure and strike it rich HA HA. I am going to try to see what I can find on the Lake Allatoona since its down about 20 feet. I am sure I will find a lot of sinkers and hooks and cans, ie Junk, but you never know I might find something worthwhile. Please give feedback, Thanks