Woof, this can be such a pain. One of the more common ones is the pump-out hatch for a septic system. In my experience, people usually do something like remember that it was on the cross-line between this tree and that tree, and that rock and this other tree. If you don't pump the septic as often as you're supposed to, the hole gets filled in, you forget, or maybe your markers have gotten shifted, and then it's miserable poking around to find that one particular one foot square spot.

Just look for the greenest grass!

https://www.goodreads.com/book/show/432288.The_Grass_Is_Alwa...

https://www.youtube.com/watch?v=QKXkfOfhmE0

> Don't bury stuff and expect to find it later.

A modern-day Turing would probably put his wealth in Bitcoin — and then lose his wallet password.

An alternate theory is that someone else dug it up first.

Doesn't seem too farfetched among "outside-the-law folks".

The story asserts the landmarks changed, but can't you pick landmarks that won't change? Better yet, use GPS and grab the Lat/Long.

That's not as accurate as you think unless you've got a full geodetic antenna. (i.e. $200k worth of equipment + a lot of permits to be allowed to have/use it) Getting to within +/- 30m doesn't help a ton when you're digging a hole to find a small box.

With geocaching, you've got something to look for. You get close-ish and then do an easter egg hunt. When it's beneath the ground, it's really hard to "look". Finding easter eggs with a shovel ain't my cup of tea.

Real-time Kinematic GPS (RTK-GPS) [1], available from Sparkfun for $200 [2] (and cheaper elsewhere), gets you centimeter accurate positioning in the US and most other countries.

[1] https://en.wikipedia.org/wiki/Real-time_kinematic

[2] https://learn.sparkfun.com/tutorials/what-is-gps-rtk/all

An extreme exaggeration. Geodetic antennas are neither regulated nor necessary. Any decent GPS receiver -- meaning less than US $100 -- will get you to within a couple of meters, even without WAAS.

Of course, in a SHTF scenario, GPS accuracy will start to degrade fairly rapidly as soon as the control stations are gone. So your point about not being able to return to the same spot is certainly valid.

Doesn't modern GPS claim +/- 3 meters, with a clear enough signal? (Which is still a heckuva lot of dirt to shift.)

Given nearby local ground-based correction stations (e.g. WAAS) it can use and flat terrain, yeah, you can certainly get that kind of accuracy.

In practice, though, I've spent a fair bit of time trying to re-occupy sites taken with handheld GPS receivers. (I'm a geologist -- it comes up a lot) 30m is a better representation of typical repeatability for a consumer-grade handheld unit or a phone.

You're often on the side of a hill, so you can't see the full constellation. If you don't have line-of-sight to more than a few satellites, you risk an inaccurate location. You're often in highly remote areas, so WAAS doesn't always help (it's based on proximity to a ground station). If you don't have WAAS, you're at the risk of atmospheric effects significantly affecting your accuracy.

There's also the user error side: You might have the handheld set to display in NAD27 one time and WGS84 another, which can easily offset the same lat/long by several hundred meters.

+/- 3m with consumer GPS is definitely possible, but that's for ideal conditions. You're rarely working with ideal conditions in the field.

The best i've ever personally got with a handheld GPS under actual work conditions was +/- 15m. I've gotten +/- 5m in large open areas lacking trees, mountains or large rock formations but areas without any of those things are rare.

Weather conditions can make a big difference. In stormy or rainy weather I was lucky if I could get +/-20m

When you narrowed it down that much you might be able to use a metal detector or similar.

You bury something and it's outside, there's no climate control, some random metal detectorist might find your thing, maybe someone will have spotted you finishing burying the thing, no saying. Just rent a storage unit or safety deposit box. Locks are better than dirt for protecting things.

Safe deposit boxes are just awful.

https://www.nytimes.com/2019/07/19/business/safe-deposit-box...

Interesting. Still better than dirt, though.

You know about continental drift, right?

Can you elaborate this more? I know about continental drifts and I know they occur at a scale much larger than a tiny box. Does it have any effect on the small scale a tiny box would be buried in if we are not burying the box near fault lines?

Australia is clipping along at 2.7”/year (about 1/16 of a meter).

That doesn’t seem like much, but in a few decades your hole is going to need to be pretty big.

IANAGeologist, but couldnt you calculate and compensate for that? Its not like continental drift is random and unpredictable (afaik, i know nothing of this subject)

Oh sure, but I know I'd get around to thinking of it after I'd moved a couple tons of dirt with a spade.