I totally agree regarding coil size. I have been at it since 1970 and back in the day most manufacturers provided an 8" coil for coin and jewelry hunting as the stock coil. The larger coils were meant for hunting caches and larger targets and this still applies today. Yes, a large coil will go deeper in general but it also loses sensitivity to smaller objects and it loses separation of targets. I have 5 coils for my Infinium, yet the 8" hardly ever comes off it. My Excal has a ten incher but I would likely rather the 8" model. I also hardly ever take my 8" coils off my safari or ATP. Most folks get caught up in the "depth hype" but I would rather have good target separation and sensitivity to smaller targets. I have no problem finding dimes at about 10" with my Safari and 8" coil, and I know for sure that on land most coins and jewelry will be found in the top 6" if there has been no soil build up by landscaping or say river silt overflow. Coins do not sink in the dirt, the dirt VERY slowly builds up over them. Like Bigscoop says, when water hunting knowing where to choose you spots is very important, and somebody with a smaller coils can easily outhunt another person with a larger coil. The smaller coil will be easier to swing in the water, and in the case of my PI it has PLENTY of depth. I can see using a larger coil for more ground coverage on dry sand, but that is about it, but even then the lower target separation ability may make hunting more tedious in the long run.