Florida divers go deep with sonar to find sunken cars, solve cold-case mysteries
The half-brothers behind Sunshine State Sonar have found 350 vehicles and 11 missing people in Florida waterways.
Florida divers go deep with sonar to find sunken cars, solve cold-case mysteries
The half-brothers behind Sunshine State Sonar have found 350 vehicles and 11 missing people in Florida waterways.
John Martin of Lakeland, left, and his brother Mike Sullivan of Gulfport suit up for a dive with their Sunshine State Sonar Search Team while investigating a submerged vehicle in the Hillsborough River at the 40th Street Bridge. Over the last two years, the divers have found 11 missing people in Florida waterways. [ DOUGLAS R. CLIFFORD | Times ]
By
- Lane DeGregoryTimes staff
Published March 26|Updated Earlier today
TAMPA — There’s a car down there, deep in the muck of the Hillsborough River. Maybe a motorcycle.
They found it the other day, out on their little boat with their fancy fish finder: a shadow on the sonar with a golden blob in the center.
Now, on a warm winter afternoon, they’re wriggling into wetsuits below the 40th Street bridge, about to dive for a license plate.
“Could be stolen,” says John Martin, 55.
“Could be a homicide,” says Mike Sullivan, 44. “You never know. There could be a body in the trunk.”
Mike Sullivan of Gulfport, right, and his brother John Martin of Lakeland use three types of sonar devices to find submerged vehicles. In late February, they were searching for a car in the Hillsborough River near the 40th Street bridge. [ DOUGLAS R. CLIFFORD | Times ]
In the last two years, the half-brothers who own Sunshine State Sonar have found more than 350 cars in canals, ponds and waterways across Florida.
Weekend fishermen turned amateur underwater detectives, the true-crime junkies dive into cold cases, searching for the disappeared. Sometimes, they choose the cases themselves, following threads online. Other times, law enforcement asks for their help.
They have discovered remains of 11 missing people inside cars, giving answers to relatives who had spent years agonizing.
One family, who thought their mom had left them, learned that she had driven off the road. Relatives of a missing teacher suspected his girlfriend — then found out he had been submerged in a canal for three years. And the son of a young mother who thought she had been murdered was relieved when her death proved a watery accident.
“You good?” Sullivan asks Martin, who is checking his air supply. Martin gives a thumbs-up.
They shove off, motoring toward a bobbing red buoy where they had marked the spot days before.
Sullivan splashes into the gray-green water, sinking through silt so thick he can’t see, feeling his way through the dark.
• • •
Martin owns a pool cleaning company in Lakeland. Sullivan, the leader, runs an auto parts business from his Gulfport home.
They both speak excitedly, spewing staccato sentences with thick Boston accents that haven’t ebbed after two decades in Florida.
“It all started with YouTube,” Sullivan says. “I kinda got obsessed.”
A couple of years ago, he got into bingeing Adventures with Purpose, videos of a volunteer dive team in Oregon that searches for missing people.
“Florida has so much water!” he told his wife. “I really need to do this.”
Sullivan has always owned fishing boats, loved catching king mackerel. He raced personal watercraft, flew airplanes, learned to read complicated instruments to navigate through the dark. A former mechanic, he knows car makes and models, can recognize hubcaps and bumpers.
And he doesn’t just watch true crime, says his wife, Johanna. “He has to go to the scene to see for himself, if it’s in Florida. He just has to be there, especially for missing people.”
He didn’t know how to scuba dive. He’d never longed to float through crystal water or over schools of colorful fish. But he got certified so he could swim through muddy channels and search waterlogged crime scenes.
He bought a shallow-draft boat and outboard motor, rigged it with the latest fish-finding technology: a Lowrance SideScan sonar, a DownScan imaging device and a Garmin LiveScope. The machines send sound waves pulsing through the water, then record them as they bounce back to create a blurry image on a monitor — like a sonogram.
It’s similar technology to what authorities are using to scour the waters off of the collapsed Francis Scott Key Bridge in Baltimore, where search crews were able to detect at least five submerged vehicles.
The equipment cost Sullivan $21,000. It took him a year to be able to interpret the images, to tell a rock from a Volkswagen. He learned that small cars sink fast and SUVs, which have bigger air pockets, sometimes float.
“He’s always been high-energy, seeking adventure,” says Sullivan’s wife, who has been with him since they were 18. “Only now it has meaning.”
Sonar scans from the search team's boat show an overturned vehicle in the Hillsborough River. Mike Sullivan spent a year figuring out how to interpret the grainy underwater images. [ MIKE SULLIVAN | Mike Sullivan ]
He started close to home, in Pinellas County, by reaching out to a cold-case detective. The officer told him about Robert Helphrey, 34. In 2006, after closing the Palm Harbor seafood restaurant where he worked, he went to a pub. Friends watched him drive away around 1:30 a.m., but no one ever found Helphrey or his Mitsubishi hatchback.
“He was a dad, a veteran,” Sullivan says. “He just disappeared.”
Over the next year and a half, Sullivan searched 150 bodies of water in Pinellas, Pasco and Hillsborough counties. “My friends and family thought I was crazy,” he says. “They were taunting me. One sent a Where’s Waldo? T-shirt.”
Sullivan reached out to Helphrey’s mom and daughter. Finally, last April, as the family looked on in shock, he found Helphrey’s car under 10 feet of water in a retention pond. For 17 years, his body had been submerged just a few miles from his home.
Sullivan doesn’t go fishing, ride personal watercraft or fly planes anymore. All of his free time goes toward searching.
Once a month, Sullivan, Martin and a couple of other volunteers go on expeditions, paying their own expenses. Last year, Sullivan says he spent $27,000 on Airbnb rentals across the state. Videos from their YouTube channel bring in about $100 a month.
“We’re blessed to have good income,” he says. “I just wish we could get a grant or something to do this full time.”
Mike Sullivan learned to scuba dive so he could search for submerged vehicles. A former mechanic and airplane pilot, "He's always been high-energy, seeking adventure," says his wife, Johanna, who has been with him since they were 18. "Only now, it has meaning." [ DOUGLAS R. CLIFFORD | Times ]
• • •
The car is upside down in the elbow bend of the Hillsborough River, nose-first, buried in sand up to its door handles.
Sullivan switches on a flashlight strapped to his left arm, takes out his phone in its waterproof case.
Swimming closer, 20 feet below the surface, he can make out a Cadillac, not too old, maybe black? The model: CTS.
On the back, there’s a Buccaneers plate — with a registration sticker valid until April 2024.
This can’t be the vehicle we’re looking for, Sullivan realizes.
A neighbor had called recently, concerned about an accident from 2019, where someone seemed to have gone over the guardrail.
This Cadillac’s demise must have been recent. Its windows are so caked over, it’s impossible to tell if anyone is inside.
“Could be an accident,” Martin says as their boat putters back to land. “Or insurance fraud.”
Sullivan nods. “Or suicide.”
Onshore, they peel off their wetsuits and call the cops.
• • •
