Alan DeWeese had just finished watching a fireworks display aboard his 26-foot Sea Ray when he heard an engine roar behind him in San Diego Bay.
He turned around, but it was too late to dodge the Coast Guard boat heading toward him in the dark.
"He came up so fast I didn't have time to react," DeWeese, 44, told The Associated Press on Monday.
His 8-year-old son Anthony Cole DeWeese died in the crash Sunday night near the 38th annual San Diego Bay Parade of Lights by the city's boating community.
Two other injured children were taken to Rady Children's Hospital, and three adults were transported to University of California, San Diego Medical Center, Fire Department spokesman Maurice Luque said.
None of the five people on the Coast Guard boat were injured.
The 33-foot Coast Guard patrol boat was responding to a report of a grounded vessel when it rammed into DeWeese's boat. Neither boat was participating in the parade.
Capt. Thomas Farris, commander of the Coast Guard's San Diego sector, declined to speculate on how fast the boats were going or answer any other questions about the crash.
"The most important thing we can do at this time is to find out what happened," he told a news conference.
The National Transportation Safety Board sent four investigators to examine damage to both vessels and determine whether there were any radio transmissions from the Coast Guard boat.
The Coast Guard and San Diego Harbor Police were also investigating.
Bob Furry was watching the parade from his sixth-floor hotel room when a boat came out of nowhere with a flashing blue light speeding through the bay. He thought the driver might have been drunk.
"We said, 'Jeez, it's going really fast.' We thought it was some kind of hot-dogger," he said.
The boat was headed east, while dozens of parade watchers were either idled in their boats or moving slowly west, said Barbara Maloney, Furry's companion.
"He was swimming upstream," she said.
DeWeese was waiting for the parade to reach him and his 12 passengers when he turned around and saw the boat. He throttled and tried to turn right.
He estimates the Coast Guard boat was traveling 35 mph to 45 mph. He said his boat had its lights on and was moving no faster than 3 1/2 mph.
"I thought, why is he going so fast? I figured he was going to turn at some point but he kept coming at us," DeWeese said.
He doesn't remember how far away the Coast Guard boat was when he first saw it.
"It happened so fast," he said. "His bow was up way high."
Furry didn't see a fire or explosion but heard a loud crunch.
"You could tell something had hit really hard," he said.
Roger DeWeese said his deceased grandson had been an ice hockey goalie.
"He was a spark plug," said DeWeese, who was not on the boat during the crash. "He liked just about everything."
He wondered how the Coast Guard operators couldn't see his boat. Still, he called it a tragic accident.
"Nobody did this on purpose," he said. "It's just one of those weird twists of fate, a cruel one."
The boy's father, also a hockey player, said his son enjoyed life to the fullest.
Alan DeWeese had borrowed the boat from his father and invited two other families to watch the parade on its 5-mile route past downtown skyscrapers and the famed Coronado Bridge.
Boaters festooned their decks with Christmas lights. In keeping with this year's theme, "Christmas at the Zoo," some participants dressed up as giraffes and pandas.
There were about 80 boats in this year's parade, from a 12-foot canoe to a 157-foot yacht.
The parade drew about 80,000 people on Dec. 13 and again Sunday, said Ron Sheehan, vice chairman.
Associated Press Writer Greg Risling in Los Angeles contributed to this report.