RedactedNarrative: Operator and his family were out on their 1995 Malibu Sunsetter. Operator's children Passenger2, Passenger3, and Passenger4 were all sitting on the swim deck of the vessel, and the vessel was idling. Operator's wife, Passenger1, was towards the rear of the vessel. Operator was in the middle of the vessel blowing up a tube. After an estimated 10-15 minutes, Passenger1 noticed their 4 year-old Passenger4 go limp. Passenger1 quickly grabbed him, and brought him back into the vessel. It was reported to dispatch that Passenger4 was unconscious. I was notified by Utah Valley Dispatch at 18:37 hours of a medical coming into the docks. I confirmed that medical had beed paded out, and then went to the dock area. Dispatch called back and gave the vessel information. By the time I arrived on scene a Provo City ambulance and fire truck were on scene and Passenger4 was inside of the ambulance with Operator. I could hear Passenger4 crying. A short time later Passenger1 and the other two children came up to the ambulance. Both children were crying and I asked if they are ok. I asked Passenger1 where Passenger2 and Passenger3 had been sitting, and she told me they had all been on the swim deck. I quickly grabbed one of the paramedics, and informed them of the possible carbon monoxide exposure of the other two. He used a pulse oxymeter to check oxygen saturation and found both children to be in the 91-94% abosrobtion range.
  
  It was decided that Passenger1 would accompany Passenger4 to Utah Valley Regional Medical Center, and Operator would follow with the other two children. The ambulance and fire truck then left. I spoke with Operator long enough to gather some information for this report. Operator sent a copy of his insurance to my email. I then asked if he wanted assistance in loading his vessel. Operator said he was going to go back out on the lake and grab the tube that they had left.
  
  I called and spoke to the State Boating Coordinator about the incident, and it was decided that a written warning should also be issued for having the kids on the swim deck while the vessel was idling. I found Operator when he arrived back at the Marina and explained the written warning to him. I also asked if I could share the experience on our social media page without using any names. I explained that it could aid in saving someone else in the future. Operator said that I could.
  
  I later found that the insurance information that Operator had sent was not an acutal policy. I sent an email back asking for a copy on the insurance policy. He sent it short time later, with a note stating that everyone was doing well. I sent a follow up asking if Passenger4 was going to be put into a hyperbaric chamber, and he responded back that he was. I will follow up again in a couple of days.
  
  There was no further incident.