I think Charlie has the right idea, the Muskie would be a deep one with the right coil, a 12 incher, and so would the Sovereign. Neither will cause you to have to mortgage the farm to purchase them either. The only problem though is that they are a bit heavy for most women.
On the other hand many, many people get really good depth with a Tesoro Silver uMax and a large eleptical coil and some swear by them for relic hunting, and the whole thing weighs barely more than half what the Muskie or Sov weighs.
An old tin bucket could be found in moderate soil 2 feet deep, with the two Minelabs above getting another foot or so, but I've dug such things before and believe me, 3 feet is a lot deeper than we think it is. Iron objects can be found at unbelieveable depths with even cheap detectors, because iron or steel produce a covalent bonding with other minerals in the soils. The bonding cause a large cloud of false target appearance, sometimes twice the size of the actual target. This is only true with iron and steel though, not with semi-precious metals.
I located an old car fender in the ground with my cz-70 3 to 4 feet deep in some real nasty highly mineralized soil. It had a factory 8" coil on it. It seemed to be almost 8 feet long, but it was only 3-4 feet long instead.
On a site in GB (Gary's?) I saw where the Silv uMax w it's large coil was the only detector/coil combination that could actually find a dime-sized English coin at 10" in mild soil, including a Minelab Explorer, DFX, etc.
In the real world, 10" on ANY dime-sized coin is a really impressive thing. Relics would be found equally as deep and deeper, depending on the size of the target.
What type objects are you looking for?
