Two people were rescued after the small plane they were in crashed in a bay off the Northern California coast Tuesday, the Coast Guard said.

The Beech Bonanza went down in Half Moon Bay, south of San Francisco, around 6 p.m. A man and woman were rescued from the water by a Coast Guard Dolphin helicopter, and both refused medical treatment, according to the Coast Guard. There were no injuries.

The plane was one of two reported to be flying together in the area, and the pilot of the second plane reported the crash to air traffic control.

Plane down in the water 5 mi outside #HMBHarbor & 9 mi south.



Both people on the plane were rescued by @USCGPACAREA



No injuries reported, but the 2 will be evaluated at a local hospital.



The cause of the crash has yet to be determined. Thank you to our partners who assisted🙏 pic.twitter.com/LhUCNwheNH — San Mateo County S.O (@SMCSheriff) August 21, 2019

"The second pilot's quick response to report the downed plane and remain on scene greatly aided the Coast Guard's prompt response and ability to save two lives," the Dolphin helicopter pilot, Lt. Cmdr. Joshua Murphy, said in a statement.

An NBC Bay Area reporter tweeted video showing the plane splashing into the water, and another video purported to have been taken by the pilot shows a woman waving at the Coast Guard helicopter while she was in the water after the crash. The video also shows the plane sinking.

NBC Bay Area reported that the pilot, whom it identified as David Lesh, was able to skip the plane along the surface of the water during the incident. A friend was in the other plane, according to the station.

Unbelievable video from pilot David Lesh, of the moment they see @USCGPacificSW come in for the rescue. His friend was flying near them when they crashed, circled around, and was able to guide USCG to their location. pic.twitter.com/SPdsuJpLpY — Ian Cull (@NBCian) August 21, 2019

Lesh told NBC News in a phone interview that he was flying with a friend and they were shooting air-to-air photos when the aircraft lost power when they were at an altitude of around 2,000 feet.

"I knew we had about 20 or 30 seconds before it sunk," Lesh said. He instructed the passenger to open the door, and they grabbed anything that would float, like seat cushions.

They were not hurt, but were starting to suffer from the cold temperatures of the water and they were stung by jellyfish, he said.

Lesh said the ordeal has left him with no reservations about flying in the future. He suspects the problem that resulted in the splash-down was fuel-related. He described the landing in the water as "basically no impact" and "a mellow impact."

The friend in the other plane, whom NBC Bay Area identified as Owen Leipelt, told the station he circled the area and radioed air traffic control without knowing whether the two people in the plane were hurt.

"Your heart sinks when you hear, 'Mayday, I have no power.' It's something you don't want to hear, and it takes a second to kick in," Leipelt told NBC Bay Area. He said that when Lesh called him 10 minutes later, "I have never been so relieved in my life to hear him on the phone."

The cause of the crash has not been determined, the San Mateo County Sheriff's Office said.