Professional surfer Kalani David has tragically passed away ... after the former Hawaiian champ suffered a massive seizure while practicing in the waters of Costa Rica.
He was only 24.
The Costa Rica Judicial Investigation Department shed some light on the accident, telling AP News "he was surfing when he apparently suffered some kind of epileptic seizure and drowned."
They added ... "The death is still under investigation."
Legendary surfer Kelly Slater paid tribute to David on his Instagram ... saying he was "one of the most talented surfer/skaters on Earth."
“Constantly pushing the limits every time he was on his feet. Condolences to the huge community of friends Kalani had coast to coast and across the globe.”
David was a gifted surfer and skateboarder ... winning the Junior World Surfing title in 2012. He also competed in several skating events.
Kalani had a heart condition called Wolff-Parkinson-White that can make the heart beat faster and cause paralysis and seizures.
In fact, David had a seizure while skating in Oceanside California in August 2016.
David's mother, Andrea, launched a GoFundMe on Sunday ... saying she needs help getting his body back to the states so she can bury him next to his grandfather in Florida.
"Our son is laying in wait at a morgue in San Jose, Costa Rica," Andrea said on the site.
"He deserved more than I could ever give him and I don’t even feel right for asking but I will for Kalani. I don’t want my son in a jar or spread on the water, as I would see fit for myself."
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Andrea added, "I want to give him a place you can go see him and know he is listening when you share your feelings with him."
"I love you Kalani! This world will never be the same without you."