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There are lots of reasons to dig holes. You might be planting a tree, installing an in-ground pool, or putting in a driveway. Or perhaps you’ve found a treasure map, and you’re digging at the X .
The best way to dig a hole depends on the size of the hole you want to create. The simplest digging tool is a shovel.
The rate at which you can dig using a shovel will depend on what kind of dirt you’re trying to excavate, but a person digging with a shovel can typically remove between 0.3 and 1.0 cubic meters of dirt per hour. At those rates, in 12 hours, you might be able to excavate a hole about this large:
But if you’re digging a hole to get at buried treasure, at some point you may want to stop to consider the economics of the situation.
Digging holes is labor, and labor is valuable. According to the Bureau of Labor Statistics, construction laborers earn an average of $18 per hour. The rate a contractor might charge for an excavation project would also include the cost of planning, equipment, transportation to and from the work site, and disposal of any waste, and likely works out to an hourly rate several times higher. If you spend 10 hours digging a hole in order to find treasure worth $50, you’re working for far below minimum wage. In principle, you’d be better off just getting a job digging up driveways somewhere, and in the end, you’d make more money than you would from the treasure.
You also might want to double-check the authenticity of your pirate treasure map, because pirates didn’t actually bury treasure.
That’s not quite true. There was one time that a pirate buried treasure somewhere. One time . And the entire idea of buried pirate treasure comes from that one incident.
In 1699, Scottish privateer * William Kidd was about to be arrested for various maritime crimes. * Before sailing to Boston to confront the authorities, he buried some gold and silver on Gardiners Island, off the tip of Long Island in New York, for safekeeping. It wasn’t exactly a secret—he buried it with the permission of the island’s proprietor, John Gardiner, along a pathway west of the manor house. Kidd was arrested and eventually executed, and the island’s proprietor handed the treasure over to the Crown.
Believe it or not, that’s the entire history of buried pirate treasure . The reason “buried treasure” is such a well-known trope is that Captain Kidd’s story helped inspire Robert Louis Stevenson’s novel Treasure Island , which almost single-handedly * created the modern image of the pirate.
In other words, this is the only pirate treasure map that has ever existed, and the treasure is gone now:
The scarcity of actual buried pirate treasure hasn’t stopped people from searching. After all, just because pirates didn’t bury treasure doesn’t mean there’s never anything valuable in the ground. People who dig a lot of holes, from treasure hunters to archaeologists to construction workers, certainly find valuable stuff from time to time.
But perhaps there’s also something compelling about the act of digging for treasure itself—because sometimes people seem to go a little overboard.
Since at least the mid-1800s, people have believed there’s buried treasure near a particular spot on Oak Island in Nova Scotia. Successive groups of treasure hunters have dug deeper and deeper holes in attempts to unearth the treasure. The actual origin of the stories is murky, but at this point it’s become almost a meta-myth: most of the evidence that something mysterious is buried on Oak Island consists of stories about evidence that may or may not have been found by previous searchers.
No treasure has been found. Even if a large chest of gold had been buried on the island, the value of the aggregate time and effort that successive generations of treasure hunters have invested in searching for it would by now almost certainly exceed the value of the treasure.
So how big a hole is it worth digging to recover different kinds of treasure?
A single gold doubloon—the classic pirate treasure—is currently * , * worth about $300. If you know where a doubloon is buried, it’s not worth it to hire someone to dig it out unless the job costs less than $300. And if you value your own labor at $20/hour, then you shouldn’t spend more than 15 hours digging it up.
On the other hand, if the treasure is a chest of gold, it could be worth a lot more than $300. A single 1-kilogram gold bar is worth about $40,000, so a chest containing 25 gold bars is worth about a million dollars. If the hole you need to dig is more than 20,000 cubic meters—equivalent to a 30 m × 30 m × 20 m hole—then it will take you so long to dig that the value of the labor involved in the digging will be greater than the value of the treasure. At that rate, you’d be better off just getting a job as a contractor doing excavation work.
The most valuable single piece of traditional “treasure” in the world might be a 12-gram gemstone known as the Pink Star diamond, which sold at auction in 2017 for $71 million. Seventy-one million dollars is enough money to hire a contractor to dig for over a thousand years, or a thousand contractors to dig for over a year. If you owned a 1-acre plot of land, and you knew the Pink Star diamond was buried 1 meter deep somewhere on your property, it would almost certainly be worth the expense to try to dig it up. But if your land were a square kilometer in area and the diamond were buried several meters down, the cost of hiring people to excavate would start to approach $71 million, and digging it up wouldn’t be worth it.
At least, it wouldn’t be worth it if you were digging with shovels.
If your planned excavation is large enough that it would take years to dig by hand, then a shovel is almost certainly not the most efficient way to do it, and you should consider slightly more modern techniques.
One more modern digging technique is vacuum excavation . Vacuum excavation involves using what is effectively a giant vacuum cleaner to remove the dirt. Suction alone isn’t powerful enough to pull apart tightly packed earth, so vacuum excavation combines an industrial vacuum with a jet of high-pressure air or water used to break up the ground.
Vacuum excavation is particularly useful when you want to dig up an area without damaging underground objects such as tree roots, utility lines, or buried treasure. The high-pressure air blows dirt out of the way but leaves larger buried objects intact. Vacuum excavators can remove many cubic meters per hour, potentially expanding the rate at which you can dig by a factor of 10 or more.
The largest holes are dug using mining excavators, which can remove successive layers of land to create open-pit mines , holes shaped like an upside-down layer cake. These holes can reach staggering sizes—the Bingham Canyon copper mine in Utah features a central pit about 2 miles across and over half a mile deep.
Oak Island, the site of the infamous money pit, is less than a mile across at its widest point. If the Bingham Canyon excavation had occurred there—with the installation of pumps and seawalls * to keep water out of the pit—excavators could have removed the entire island and the underlying bedrock down to a depth 10 times deeper than the deepest shaft dug by treasure hunters.
The material could be carefully sifted through to search for any treasure, putting an end to the mystery once and for all.
Using industrial excavation and drilling methods, humans are capable of digging huge holes. We’ve removed entire mountains, created vast artificial canyons, and drilled shafts a significant fraction of the way through the Earth’s crust. As long as the rock is cool enough to work with, we can dig holes as deep as we want.
But should we?
In 1590, more than 300 years before the Panama Canal was built, the Spanish Jesuit priest José de Acosta discussed the idea of digging a channel through the isthmus to connect the two oceans. In his book Historia Natural y Moral de las Indias , he speculated about the potential benefits and pondered some of the engineering challenges involved in “opening the earth and joining the seas.” He ultimately decided it was probably a bad idea. Here’s his conclusion, from the 2002 translation by Frances López-Morillas:
I believe that no human power is capable of tearing down the strong and impenetrable mountain that God placed between the two seas, with hills and rocky crags able to withstand the fury of the seas on either side. And even if it were possible for men to do it I believe it would be very reasonable to expect punishment from Heaven for wishing to improve the works that the Maker, with sublime prudence and forethought, ordered in the fabric of this world.
Theological questions aside, there’s something to be said for his humility. Humans are capable of unlimited excavation, from backyard shovel digs to canal construction to industrial strip mining and mountain removal. And by digging holes, we can certainly find things of value.
But perhaps—sometimes—it’s better to just leave the ground the way it is.
