The scream came from the ocean off the private Kukio Golf and Beach Club on Hawaii's largest island where, moments before, a man had been stand-up paddleboarding.

There's no lifeguard on the beach at the private community, but there is a "private safety team" that launched a four-person canoe.

In the water, they found "a male individual who had been bumped off his paddle board about 90 to 140 metres offshore," Fire Captain Michael Grace told Honolulu Fox-affiliate KHON. "They recovered him from the ocean. He had injuries to his right-side extremities."

The 25-year-old man was flown to hospital with critical injuries. Credit:Paul Johnston

On the beach, bystanders and staff members tended to the man's wounds, applying multiple tourniquets before paramedics arrived, Grace said.