Turn it ON. Auto GB and Tracking are 10 times more accurate than you are, and 100 times faster.
I haven't done any nugget hunting but at some point I am going to give it a try....soon.....is that 10"x 5" coil any good on coin shooting...
Some in your area like it for a coin shooter, and some use it for nugget hunting too (it's the stock coil in the Gold Pack), but it's not the optimal for either. The 6" HF DD is the most sensitive to tiny gold (like as small as .02g), separates very well, and is waterproof. By nature of being only a 6 inch coil it is depth limited, but it will get virtually the same depth of the "water resistant" 5x10".
For a coin shooter, I like the Coiltek 6" 3kHz DD "Digger", and the Coiltek 15" 3kHz DD All Terrain, but they may not be suitable in your ground. You
will want to stick with DD coils regardless of which frequency you choose because they handle high mineral levels better. The 10.5" DD 7.5kHz is a great coil for general use. MF coils have the most uniform target segment bin widths, so they are the most honest across the detection range. The HF 10.5"
could be a good coil for you, because that frequency has better resolution on low conductors in the range where you find iron, nickels, and gold. It will hit on all metals, but it won't be as accurate on high conductors like aluminum, copper, & silver.
How much do you wish to hunt in water? That makes a difference too. Of the 12 coils authorized for use on Xterras by Minelab, only three are NOT waterproof. Perhaps unfortunately, they are the two 10.5" DD coils and the 5x10". The 9" coils are all waterproof, as are the 6" coils, but the 9" coils and 6" MF coil are all Concentric. All three frequency Coiltek 15" DD coils are waterproof.
Along with the free e-book that Randy Horton wrote, he also has written a few blog articles for Minelab, and among others he wrote one about Xterra coil selection. You should probably check it out.
Which X-TERRA coil is best for me? part 1
Which X-TERRA coil is best for me | Treasure Talk
Which X-TERRA coil is best for me? part 2
Which X-TERRA coil is best for me? | Treasure Talk
Which X-TERRA coil is best for me? part 3
Which X-TERRA coil is best for me? - Part 3 | Treasure Talk
Which X-TERRA coil is best for me? part 4
Which X-TERRA coil is best for me? - Part 4 | Treasure Talk