Missing paddleboarder's family makes online plea urging navigation company to release his location data

The family of a "professional diver and spearfisher" is calling on a navigation company for help after Luciano Mercenari went missing this week while paddleboarding off the coast of Key Biscayne, Florida.

Mercenari was wearing a GPS-enabled Garmin brand diving watch at the time of his disappearance, his cousin, Allegra Jacchia, said in a social media post urging the company to release the location data.

Jacchia's post went viral, sharing the hashtag "#FindLuc," tagging Garmin in hopes the company will take further action in locating Mercenari.

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"He was wearing a watch from the brand Garmin, a diving watch," Jacchia said. "We contacted the brand, who told us that since the watch had not been synced to the phone since March, there is no way to track his location." 

"We asked for more information; we are begging them to help us find a way."

According to Jacchia, after a public pressure campaign, Garmin is sending out a team to locate Mercenari Thursday with sonar devices. This is yet to be confirmed by Garmin.

A Garmin spokesperson told Fox News Digital in a statement, "We know this must be incredibly worrisome for family and friends of Luciano Mercenari."

"Garmin has been in touch with local police in Key Biscayne since early Tuesday morning and have responded to inquiries from family members via email. We will continue to do whatever we can to support efforts to locate Luciano."

Mercenari was last seen on surveillance video leaving his residence just after 5 p.m. Monday, according to the Key Biscayne Police Department. He was wearing a "long white sleeve shirt, black and red shorts," and was carrying a gray backpack, police said.

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"Please know he is a professional diver and spearfisher. He knows the water very, very well, so it was not unusual for him to do this," Jacchia said in a statement to Fox News Digital.  

His paddleboard, a teal and orange Niphean inflatable, was found intact nearby sometime between 10:30 a.m. and noon Tuesday by good Samaritans, who reported it to police, according to Jacchia.

In addition to his paddleboard, Jacchia said that "[Luciano's] wet bag [was] on it, including a mask, snorkel, gloves and water bottle. The paddle board was found 3½ miles off the coast of Pompano."

Florida Fish and Wildlife officials, the U.S. Coast Guard, and Miami-Dade and Key Biscayne police are involved in search efforts for Mercenari with "boats, helicopters and planes looking for him," Jacchia said. "We are doing everything we can to find him. We are a very close-knit family, and we are so distressed, but we are not losing hope." 

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Key Biscayne police did not immediately return Fox News Digital's request for comment. 

Anyone with information on Mercenari's whereabouts is urged to contact Key Biscayne police at 305-365-5555.