A 17-year-old Farrington High School student who died Sunday after being run over by a fishing boat in Mamala Bay off Hawai'i Kai was remembered yesterday by family and friends as a "church boy" who had a pure heart, a love of dirt biking and a passion for free-diving.

And, Keahihoku Lum of Kalihi was a stickler for diving safety, his diving companions and those who introduced him to the sport said.

Those who loved and dived with Lum were shocked by initial news reports that suggested he and two fellow divers were in the channel near the bridge on Kalaniana'ole Highway that spans the channel entrance to Koko Marina when they were run over.

Kiana Onishi, who was with Lum when he made his first free dive off Laniakea on O'ahu's North Shore a year and a half ago, said she spoke with Lum's diving partner who was injured in the same incident and got the following account from him:

All three entered the water from a right-of-way makai of the "China Walls" area on Portlock Point. Each of the divers had a "diver down" flag attached to a float they towed behind them.

They were diving 100 to 200 yards off the shoreline when one of the divers' speargun shafts got stuck in the rocks or coral on the bottom.

He surfaced to tell Lum and the other diver about all the fish he had seen in that spot and told them to swim a short distance to where he was and to dive down in the same area.

The diver whose spear shaft was stuck took a breath and went down after it. On the way back up, he heard the sound of a boat passing overhead. When the diver surfaced, he learned that Lum and the other diver had been hit by the boat. Both were injured, Lum severely.

The diver with Lum yelled at the boat operator to stop, and he did. The boater took the two injured divers to shore at the Hawai'i Kai boat ramp where police, firefighters and city paramedics were waiting.

Lum was taken to The Queen's Medical Center, where he was pronounced dead.

The city Department of the Medical Examiner conducted an autopsy on Monday and determined his death was due to lacerations of the chest and abdomen caused by the boat's propeller.

"These are all good kids, kids who do the right thing and follow the rules," Onishi said yesterday. "All three had buoys and all three had (diver-down) flags. They did everything within their power to make it a safe dive."

The ocean off China Walls was a favorite haunt for the three and they had dived there many times, Onishi said.

The diver who was injured along with Lum also was taken to the hospital following the incident, and has since been discharged and is taking his friend's death "very hard," Onishi said.

The wetsuit hood Lum's dive buddy was wearing has three deep slashes in it from being hit by the spinning boat propeller, Onishi said.

She said Lum appeared to be hooked on free diving after his first experience off Laniakea in 2008.

"We were all wearing wetsuits except for him — he only had a rash guard. We got there at 6:30 and were in the water by 7. It was pretty cold and he was cold, but he was determined to stick it out."

Within months, Lum had acquired full wetsuit regalia, including the long fins and a wetsuit of his own and was beginning to excel at diving.

"He was kind of shy and quiet at first, but later on he really opened up," Onishi said.

One thing that stands out in her mind is how "clean and respectful" Lum was in his conversations with her and others.

"He never swore and he never talked about drugs or drinking. He loved to talk about diving or school or the church activities and the video games he was into," Onishi said.

Lum's mother, Lehua, was making funeral arrangements yesterday and did not want to talk to the media, her sister, Luana Kin Choy, said.

Kin Choy, who is from Maui, flew to O'ahu to be with her sister following Keahi's death.

"He was a church boy — he didn't smoke, he didn't drink," Kin Choy said of her nephew. "He belonged to the New Hope Christian Fellowship."

Kin Choy said Keahi Lum had two sisters, one younger than him and one older.

Lum, his mother and one of his sisters lived in an apartment in the Kalakaua Homes area right across the street from Farrington High School, Kin Choy said.

"All-around good boys — those are real hard to find. This area in Kalihi, it's kind of rough. Sometimes it's tough to be a good boy like Keahi was."

Kin Choy said Keahi had a girlfriend, wanted to go to college to become a chef, but had also expressed thoughts about becoming a firefighter like his grandfather, Hung Bung Lum.

BOAT PROPELLERS CAUSED 3 OTHER DEATHS SINCE '94

During the past 15 years, there have been three other fatalities related to injuries caused by boat propellers, according to state Department of Health statistics. There was one each in 1994, 2000 and 2006, the records show.

The first two incidents involved swimmers or divers being run over in open water. The most recent happened when a person fell off his boat into the propellers, said Dan Galanis, an epidemiologist with the Injury Prevention and Control Program of the state Department of Health.