All-Metal mode is the deepest mode; HOWEVER, coin-sized objects will still ID to depths of only 12" or so. The depth at which a target will properly ID in the ID mode..... is the same depth it will properly ID in the AM mode (F-75 & T-2). Yes, targets will audibly report to greater depths in the AM mode...... but the VDI screen will remain blank on the deeper targets. Now,,,,,,, that being said...... IF you are a extremely seasoned hunter...you can take advantage of these greater (no VDI) deeper depths. If you can audibly 'profile' deep/weak targets, you are in for some serious enjoyment. Can you tell the difference between a small target that is shallow, , , such as a lead .22 Short 29Gr rimfire projectile at 4" deep vs. a U.S. nickel at 12" depth. These are both non-ferrous targets. ....... And can you tell the difference between a 2-Penny nail at 7" vs. a Wheat penny at 12". This latter example... is the MOST common and MOST important test for the astute detectorist,,,, as it poses the greatest challenge with the most significant, rewarding resultant. Of note; Dinosaurs are miles beneath the Earths surface. Egyptian sunken cities are dozens of feet deep........ thusly; the 100 year-old coins we wish to find are a foot or two deep.
Tom