MIAMI -- If the ocean had highways, the intersection at the Dry Tortugas and the Florida Straits might well have ranked among the planet's most dangerous, at least in ye olde times.
Ships threading its treacherous reefs wrecked for centuries, sometimes at a rate of once a week, leaving behind an untold fortune in booty. Key West was built on a good chunk of those spoils. And modern-day treasure hunters still scour the region in search of loot. Which is why the National Park Service, guardian of a vast swath of potentially wreck-laden waters in Dry Tortugas National Park, has for the first time started surveying the deep waters within its boundaries.
While no one knows for sure what remains on the sea floor, it could be bountiful: since 1988, federal law has largely blocked treasure hunters armed with new technology that one marine archaeologist says has allowed any "halfwit" to strike gold.
"Can you imagine what would have happened if 120 years ago every archaeological site in Egypt had been dug up?" said Filipe Castro, a professor of nautical archaeology and director of the Ship Reconstruction Laboratory at Texas A&M. "Anybody can get a magnetometer and side-scanner. These people are finding shipwrecks nonstop and sacking them and destroying them."
Park officials hope to preserve what's left of the historical record of what was once a main thoroughfare between the old world and the new. If possible, the survey could also add sites to an underwater trail of identified shipwrecks that stretches along Florida's reef between the far islands and Miami.
So far, searchers have turned up two intact wrecks and a good deal of debris with no historic relevance: a cement mixer, a television console and more milk crates than they care to count.
"Probably 85 percent of the time it's modern trash," said Dave Conlin, chief of the agency's Submerged Resources Center. "We're finding the equivalent of pop tops and tin cans. But then the other 15 percent of time it's an anchor or a cannon or very occasionally it's a shipwreck."
But treasure hunters, long at odds with the government over rights to salvaged ships, fear the survey is an attempt to stake out items that belong to claimed wrecks.
"We have a federal ruling from back in the '70s that if anybody does come upon stuff, we could claim it and would probably win in court," said Joe Sweeney, director of administration for Mel Fisher's Treasures, the family-run company that continues to search for spoils from the Nuestra Senora de Atocha, the treasure-laden Spanish gallon found near the Marquesas Keys 38 miles to the east. "So if the park service stumbles upon six or seven cannons out there, they better give us a call."
The Dry Tortugas make what sailors call a perfect recipe for a shipwreck. Low land, a large fringe reef, tides that vary with the seasons and a strong current. Toss in a hurricane and you've got the makings for a high speed collision.
At the center of the intersection sits Garden Key, which in the mid-1800s became home to one of the nation's biggest coastal forts, the massive six-sided Fort Jefferson. Built over 40 years, the fort was abandoned without ever being fully operational.
When President Franklin D. Roosevelt made the fort and surrounding waters a national monument in 1935, any wrecks within its boundaries officially became U.S. property. Taking anything off the wrecks is illegal and comes with hefty legal penalties, including fines, imprisonment and forfeiture.
While wrecks in shallow waters have been well-documented over the years, deep waters remained unsearched.
Part of the problem is the expense: looking for wrecks in deep water requires a magnetometer, a giant, torpedo-shaped metal detector trailed behind a boat, and expensive dives to confirm findings. The surveys can only be conducted during calm, summer months.
"We don't know from just looking at what the sensor finds whether the metal is a shipwreck or a modern shrimp boat or whether it's a cannon or an anchor," Conlin said.
The search can also be painstakingly slow. Over the summer, divers surveyed just a tiny patch of deep water, spending much of their time picking through fishing traps and other modern debris.
In 1971, civil war historian Edwin Bearss, now the agency's chief historian emeritus, documented 20 wrecks in the park dating from the 17th century. He located at least another 195 in historical records, but money and time prevented Bearss from searching Bahamian records, which he said likely would have revealed far more.
A clearer indication of the number of wrecks might be the successful history of wreckers, who date back to the Calusa. After the tribe was wiped out by European disease or captured and enslaved, Bahamian turtlers and fishermen took over. The Bahamians set up the first legal wrecking operation with rules, admiralty fees and a reasonable split between the wrecker and the ship's owner. Most deals were hammered out in Tavernier -- because it was located closest to the most dangerous reef in the Keys, Carysfort -- and Upper Matecumbe, which had fresh water and good anchorage, according to Bearss.
When the U.S. took over Key West, Bahamian wreckers got shoved to the side.
With the exception of the military, wrecking served as the Keys' chief industry. In 1826, Congress created a new southern judicial district court in Key West to oversee the sometimes ruthless wreckers trolling the reefs. Formalizing wrecking, "an innovation never introduced in any other United States judicial district, seems to have been suggested by the more responsible element in Key West," wrote historian Dorothy Dodd. By the late 1850s, Dodd said the value of ships and cargo passing shipped through the region amounted to $300 million to $400 million annually.
The wrecking industry, however, soon started to decline after the U.S. finally commissioned a more thorough survey of the reefs, erected more lighthouses and many ships switched to steam engines. In 1921, the wrecking license registrar in Key West closed up shop.
In place of wreckers, a new entrepreneur appeared: the treasure hunter. From the 1950s to the '70s, Castro said most shallow wrecks were picked clean.
"They found cannons and silver coins, and put everything in their front yards," he said.
Like the secrecy that shrouds treasure hunting, the park service is also reluctant to give details about its finds for fear wrecks will be illegally salvaged. The service also rarely removes anything from the wrecks, Conlin said, because officials would rather preserve what's left intact.
"Would you rather see a grizzly bear in Alaska with your children or would you rather see a grizzly at the zoo? The same holds true with shipwrecks," he said. The park would rather have its visitors "stumble on an old anchor and say what in the world is this? You can have that moment of thrill and discovery and connection to the past that is unregulated. That is raw."
If a wreck has objects easily removed, park officials keep it protected. If not, Conlin said his crew will recommend it be opened for diving. Only the widely popular Windjammer site and other smaller wrecks on shoals to the northeast of Fort Jefferson are now marked on park maps. Park officials are also shooting 3-D imagery that will let them keep track of the wrecks in case of hurricanes or looting. The film will be used in a video for visitors at other more accessible places in Key West and at Everglades National Park.
Of the two wrecks located over the summer, Conlin said one turned out to be a modern-day fishing vessel that likely sank in the past five years. The other is still being studied.
Divers have also found, mostly in shallow waters, reefs "festooned" with anchors, suggesting many captains successfully applied their ships' "brakes," escaped and left the anchor behind. They've also found numerous homemade boats powered by lawnmowers, car engines, paddles and sails likely piloted by Cuban refugees, as well as piles of bricks intended for Fort Jefferson.
"In some ways, those are the most archaeologically satisfying because they make sense," he said. "It's a very easy Sudoku puzzle to solve for Fort Jefferson."
Aside from treasure, the wrecks often provide an invaluable record of lives not often documented in history: the illiterate sailors and slaves often aboard ships.
"For hundreds of years, sailors were not generally literate, so the people who wrote stories about sailors were wealthy ship owners and captains, and they had a particular story to tell," Conlin said. "So the archaeology of shipwrecks is the archaeology of everyday people who didn't write. They didn't leave a lot behind. But in the small things they did leave, we can come to some illuminating insights into how they lived their lives."
The wrecks and artifacts within the park and other protected areas also become increasingly important as the number of untouched wrecks declines.
Until 1988, salvage laws governed wrecks, regardless of their historical importance. With little law enforcement on its staff, park waters were vulnerable to the same salvaging happening throughout the region despite rights spelled out in national park rules. But when Ronald Reagan spelled out protections for wrecks -- prompted by Fisher's famously persistent fight for his rights to the Atocha in protected waters in the Florida Keys National Marine Sanctuary -- that helped end widespread salvaging of historic wrecks in U.S. waters.
Because Fisher won his suit, Sweeney said the company's claim extends to finds outside a 10-by-4-mile area in the sanctuary that could belong to the ship. And because the Atocha sank during a hurricane and rolled over in quicksand, Sweeney said its artifacts could be scattered far from the wreck site.
"We obviously as treasure hunters are very leery of what the government is doing. They're taking over more and more of the ocean bottoms," he said. "It's no secret that (the National Oceanic and Atmospheric Administration) would like salvagers out of business."
Surprised to hear about the mapping project, Sweeney said he asked around and no one else had heard about it either.
"Obviously if they find anything, we'd like to know because there's still eight cannons and $350 million out there," he said.
Castro, the Texas A&M professor who has researched shipwrecks around the world, believes it is unlikely park officials will find wrecks not already picked over. But that shouldn't stop researchers from looking.
"These sites can be filmed and made into virtual reality and visited by any kid in any school without destroying them and then we can go down and dig a trench and try to understand the site better," he said. "This is the wealth and the planet we want to leave for the future. It doesn't make any sense to let treasure hunters destroy them or destroy them ourselves as archaeologists."