Irby Lacheney jumped into a boat and rushed out onto California's San Pablo Bay just moments after two planes collided, but when he got there he found just debris, paper and an oil slick.

"It's tough when you have a situation like this…it's like 'poof,' they're gone," Lacheney told ABC News today.

The search continued today for one of two small planes that collided Sunday evening following an air show. One plane carrying a husband and a wife landed safely at a nearby airport. The other plane plunged into the water.

Search crews are looking for the pilot after his aircraft crashed into another small plane. Credit: KGO.

Investigators arrived on scene this morning in Point Richmond, Calif., where the planes collided, but have not yet recovered the missing plane, National Transportation Security Board's spokesman Terry Williams said.

Lacheney, a retired diver, was one of the first people to arrive at the scene with members from the nearby lighthouse.

"I heard the motors of the two airplanes flying over the harbor and then a few minutes later, people were hollering outside that two planes had collided," Irby told ABC News. "All I could think was 'I need to get there as soon as possible.'"

Lacheney hopped on the East Brother Light Station lighthouse boat around 4 p.m., where he and a crew immediately headed out a few miles out to the accident. But all they found was scattered papers that appeared to have come from the plane's cockpit, something that looked like an arm rest and an oil slick.

Twenty minutes after they arrived, Lacheney said that Coast Guard officials took over the search.

"It's tough when you have a situation like this…it's like 'poof,' they're gone," Lacheney said.

The two single-engine planes, the Cessna and the Hawker Sea Fury TMK 20, were flying together after attending the annual Pacific Coast Dream Machines Show at The Half Moon Bay. The planes were featured in a popular event that showcases over 2,000 motorcycles, cars, and airplanes. The accident happened after the event on their way home, authorities said.

"It was a great day yesterday, unfortunately with a bad ending," said Timothy Beeman, director of the Pacific Coast Dream Machines Show. "Nothing like this has ever happened before."

The passengers in the plane that landed safely at the Eagle's Nest Airport were not injured, according to the airport manager David Wardall.

The NTSB said that they do not release names of people involved in transportation accidents.

The investigator plans to interview the pilot of the Hawker Sea Fury today, according to Williams.