The inquest has been held into the death of popular surfer Jacob Cockle, who drowned after swimming at a place locally famous for its whirlpools last May.
Coroner Andrew Cox has warned people to stay away from the water at the area following a verdict of accidental death at the inquest.
The 28-year-old was found floating face after being sucked down and dragged through a 12 metre sluce tunnel at Carnsew Pool at Hayle on May 28.
He was filming the whirlpools, something he had done previously, when he was sucked down.
Despite being pulled from the water and resusitated, he was confirmed dead after being airlifted to Royal Cornwall Hospital at Truro.
The "competent swimmer" was described as a "risk taker".
Coroner Andrew Cox, recorded a verdict of accidental death, calling it a "tragic event" and a "warning to anyone else contemplating swimming in the same area".
The area has now been fenced off and warning signs are in place to dissuade any swimmers.
The whirlpools are formed as the tide fills the harbour. These are not naturally occurring and instead occur because large pipes under the water.