A Florida man who was critically injured after kitesurfing on a beach is recovering from his injuries.

Falk Weltzien, 39, was on Vilano Beach Monday with his 14-year-old son, Kai, when he was struck, the St. Augustine Record reported.

For a moment, Kai, thought he had lost his father.

"There's like a big white flash," Kai told ABC News. "I dropped my kite and then I looked over and I saw him laying on the ground."

Weltzien, of St. Augustine, had been hit by as much as one billion volts, enough electricity to light up a small town.

"When I looked at him his eyes were open and he was foaming from the mouth," Kai said. "Then I didn't look at him anymore because I was really scared."

An off-duty nurse who was nearby performed CPR.

In a 911 call for the incident, Kai could be heard telling the emergency operator that his father was turning blue.

"Make sure he's breathing," the dispatcher replied, advising that CPR be performed on the stricken man.

Weltzien was taken to Flagler Hospital. After a night in the intensive care unit, he survived with no major injuries.

"I'm feeling very thankful," Falk Weltzien said. "I know I could have been dead."