HONOLULU (HawaiiNewsNow) - Kristen Fonseca and her family were here for a weekend getaway from Vacaville, Calif. Her step dad called her "Krissy."
"She was the youngest. She was our baby," Mario Canton said. "I would like her to be remembered as happy, adventurous, glowing, innocent, and just smart."
He said Kristen could light up a room, loved to dance, and loved thrill rides. She had been on jet skis before.
"She was an adrenaline junkie. She liked jet skiing, she liked really wild roller coasters, anything that would get her going she loved that type of activity," he said.
On Sunday, Canton and his two step daughters rented jet skis from Aloha Jet Ski Rentals. He was standing on the dock at Keehi Lagoon. He said Kristen saw him and slowed down but the rider behind her didn't
"I looked over and I saw the other guy come in at a very high rate of speed on his jet ski, looking toward the dock. So he was not looking in front of him," he said.
Canton said he shouted for the man to look ahead but it was too late.
"He ran into the back of her jet ski. I noticed that she hit her head against the steering wheel and then she fell into the water," he said.
Canton said he jumped in to rescue his daughter. He estimates the water craft that hit her jet ski was traveling at 40 mph at impact. The medical examiner said Kristen died of a brain injury.
Canton said he relives the scene "every day, every minute."
Aloha Jet Ski is licensed to operate in a section of Keehi Lagoon. Hawaii News Now's requests for comment from the company were not returned.
"There was no speed limitations briefed," Canton said. "The only safety issue that he mentioned was make sure no one's in front of you."
Canton said he and his family keep asking themselves, "What if?"
"The what if's of, 'Should we not have come to Hawaii?' The what if's of, 'Should we not have gone jet skiing?' My son is really beating himself up with, 'What if I was there?'" he said.
Kristen wanted to be a nurse. She was set to start as a volunteer at a Vacaville hospital. She would have been a junior at Vacaville High School. She was 16.
The Visitor Aloha Society of Hawaii is assisting the family.