The father of an 8-year-old boy killed in a collision with a Coast Guard vessel said Monday he saw the craft speeding moments before it slammed into his boat and seriously injured five other people near a Christmas watercraft parade.

Alan DeWeese, 44, of San Diego told The Associated Press he tried to get out of the way of the Coast Guard boat he estimated was traveling 35 mph to 45 mph. DeWeese believes he was moving no faster than 3 1/2 mph.

"I thought he was going to turn at some point," DeWeese said. "He came up so fast I didn't have time to react."

Killed in the accident was DeWeese's son, Anthony Cole DeWeese.

"He enjoyed life to the fullest," his father said.

Two other children were taken to Rady Children's Hospital, and three adults were transported to University of California, San Diego Medical Center, said Fire Department spokesman Maurice Luque.

Their conditions and ages were not immediately available. Seven others on board weren't injured. No one was reported injured aboard the Coast Guard vessel.

The Coast Guard declined comment, citing an ongoing investigation.

The National Transportation Safety Board was sending four investigators to San Diego, said department spokesman Peter Knudson. They will examine damage to both vessels and determine whether there were any radio transmissions from the Coast Guard boat.

The 33-foot Coast Guard patrol boat was responding to a report of a grounded vessel on Sunday when the accident occurred while a Christmas watercraft parade was under way in San Diego Bay, authorities said. Neither boat was participating in the annual event that was expected to attract as many as 80,000 people.

DeWeese said the people aboard the 26-foot Sea Ray had just finished watching fireworks and were waiting for the parade to begin. He said he recalls hearing the Coast Guard boat coming from behind but couldn't estimate its distance.

"He was the only boat that was going so fast in the harbor," said DeWeese, who was released from a hospital. "His bow was up way high."

Bob Furry and Barbara Maloney said they were in their sixth-floor hotel room when they saw a boat traveling west with a blue flashing light on its bow, going much faster than the rest of the boats in the harbor.

"We thought it was some kind of hot-dogger," Furry said.

Furry didn't see the crash but heard a crunching noise.

"You could tell something had hit really hard," he said.

He didn't see any fire or an explosions.

DeWeese's father, Roger, who owns the boat, said he went to the hospital and talked with his daughter-in-law and others, who told him the Coast Guard vessel was heading east at high speed then turned around before the crash.

He said his boat was equipped with a light on its stern and he had made sure all the children had life preservers before the boat went out on Sunday with three families aboard.

Roger DeWeese has fond memories of his grandson Anthony, saying he was an ice hockey goalie and was confident and intelligent.

"He was a spark plug," DeWeese said. "He liked just about everything."

He wondered how the Coast Guard operators couldn't see his boat on Sunday but believes the crash was a tragic accident.

"Nobody did this on purpose," he said. "It's just one of those weird twists of fate, a cruel one."