Real-time buoys to be placed off 3 beaches.

WELLFLEET — With little fanfare, shark detection technology on Cape Cod took a small step forward last weekend off Newcomb Hollow Beach, the site of last year’s fatal shark attack on bodyboarder Arthur Medici.

Cape Cod and regional public safety officials have been hoping for years to employ a kind of souped-up version of what they already have, an acoustic receiver attached to a buoy that can not only detect signals from tagged great white sharks but relay an instantaneous alert to lifeguards and beach administrators.

One such device was deployed off Newcomb Hollow on Saturday, state shark researcher Gregory Skomal said, and two more will be placed offshore next week, one at Head of the Meadow Beach in Truro and the other at Nauset Beach in Orleans.

“The basic premise is that anytime a shark swims within range of a receiver it is detected. Only in this case, the data is forwarded as quickly as possible via a cellphone signal to whoever you want notified,” said Skomal, a senior scientist for the Massachusetts Division of Marine Fisheries.

A total of 171 sharks have been tagged since 2009 with acoustic devices that broadcast a unique identifying signal that is picked up by a necklace of receivers attached to buoys off popular Cape beaches. The distance at which the receivers can detect shark signals depends on water clarity and other factors affecting underwater sound transmission, such as wave noise and vessel traffic, but Skomal estimates a shark passing within 330 to 660 feet of the buoy would be detected.

“This is somewhat of an experiment,” Skomal said, as he is working with engineers in Germany and in Canada to make the best use of buoy performance. Buoys from two companies are being tested: VEMCO, a Nova Scotia-based firm that already supplies the acoustic receivers used by Skomal, and Customized Animal Tracking Solutions, a firm based in Germany that makes the accelerometers that Skomal has put on some sharks to investigate fine-scale movements.

These buoys are powered by a solar panel, and each unit, along with data processing charges, will likely cost between $10,000 and $14,000, Skomal said. The Atlantic White Shark Conservancy, a nonprofit organization that raises money in support of Skomal’s research, bought one of the receivers to be tested at Nauset.

The goal is to have the shark alert go out immediately after the signal has been received, but the Outer Cape’s poor cellphone reception has caused lag times in notification. Emailed alerts from the Wellfleet buoy were received two to seven minutes after the shark detection, Skomal said, from a half-dozen sharks. He hopes the Nauset buoy, with an upgrade to a faster modem and better cellphone reception thanks to improvements that Orleans and Verizon made to enhance the signal, will reduce the gap between detection and alert.

“The good news is that CATS engineers are following every aspect of this and they are seeing places where it could be improved,” Skomal said. He believes the testing will result in a newer version with improvements.

The Wellfleet buoy is positioned in 20 feet of water a couple of hundred yards offshore to compensate for the poor reporting times and in the hopes of getting a better signal.

“We didn’t want to put it in where people were swimming and have the notification be late,” Skomal said, but he thinks reduced lag times would result in placement closer to beaches and the swim area.

“We’d like to see the notifications be almost instantaneous,” he said.

Wellfleet Beach Administrator Suzanne Grout Thomas said they were connected to the system Tuesday with email alerts about three sharks sent to her and to head lifeguards at town beaches. Skomal said towns would have to determine for themselves whether an alert merited closing a beach to swimming. Thomas said a shark detected in 20 feet of water, even at 300 feet from shore, could make it to shore fairly quickly and would result in a beach closure, which did occur Wednesday at Newcomb Hollow.

She was encouraged that viable technology was at last becoming available to towns.

“It gives me some hope that we’ll be able to do something solid for people,” Thomas said. This is not a panacea: The real-time buoys detect only tagged sharks, and researchers have identified more than twice the number tagged. It will take a matrix of technologies and policy to actually make people safer, Thomas said.

“At least we’re moving toward something,” she said.

— Follow Doug Fraser on Twtitter: @dougfrasercct.