RedactedNarrative: SYNOPSIS
  
  A pontoon boat on Abiquiu Lake experienced hull failure and is presumed to have sunk.
  
  NARRATIVE
  
  On Thursday, July 8, 2021, I was notified of a boating incident that had happened at Abiquiu Lake on June 25, 2021.
  
  On Friday, June 25, 2021, U.S. Army Corps of Engineers (USACE) rangers responded to a call of a disabled pontoon boat. Rangers 1, 2, 3, and 4 located the boat near the mouth of the lake channel. According to Ranger 1 the boat was listing badly, so he decided not to attempt to tow it. All eight passengers were loaded onto the rangers' patrol boat. While the passengers were collecting their things from the disabled boat, rangers noticed alcohol on board. The disabled boat was tied off to shore. Rangers transported all passengers to the Abiqiuiu boat ramp. Rangers 1 and 4 then returned to the disabled boat and noted that it had sunk much deeper in the water and it would be dangerous to move (Photographs 1 & 2). That evening the owners returned with a second boat. However, they stated that they were unsuccessful in towing their disabled boat back to the ramp.
  
  On Saturday, June 26, 2021, Ranger 1 observed that the pontoon boat was gone. He observed a significant amount of flotsam near where it had been tied off: inner tubes, life jackets, seat cushions, and the entire captain's seat of the boat (Photograph 3). Ranger 1 then swept the lakebed with sonar. About 100 feet offshore from where the captain's seat was, Ranger 1 found what appears to be a sunken pontoon boat with a retracted bimini top (Photographs 4–6). Ranger 1 contacted Passenger 1, who insisted they had gotten the boat off the lake. Ranger 1 requested that Passenger 1 email him a photograph of their boat as proof, and come to claim the captain's seat. Ranger 1 has not received a response from Passenger 1.
  
  On Thursday, July 8, 2021, I traveled to Abiquiu Lake. I located the site where the pontoon boat had been left the afternoon of June 25. I observed a deflated green inner tube on the rocks (Photograph 7). Using side-scan sonar, I located what appears to be a sunken pontoon boat with a retracted bimini top (Photographs 8–14), located about 150 feet nearer to the Abiqiuiu boat ramp than where it was left on June 25. I noted that the bow (front of boat) faces toward the boat ramp. This indicates that the boat may have sunk during an unsuccessful attempt to tow it back to the ramp. The location is 36°16'23", -106°29'9". Water depth is about 40 feet.
  
  In my interview with Ranger 1, I learned that while rescuing the boat's passengers he observed a 30-pack of beer, a fifth of vodka, a fifth of tequila and "minis tucked in little pockets" throughout the boat. In my interview with Ranger 2, she told me the boaters said they'd dropped anchor to swim and then couldn't start the motor. In my interview with Park Manager, he told me that the boat's "pontoons were ripped".
  
  Based on my investigation, I am unable to rule out that a lack of or inadequate vessel flotation caused by pontoon failure contributed to the incident; and that use of alcohol by the vessel operator or passenger(s) contributed to the incident.
  
  This narrative is based on USACE incident report and Ranger 1's emails to me (attached), my witness interviews with USACE rangers, and my personal observations at the incident site. Passenger 1 has not yet returned my calls in attempt to contact him for an interview. Further follow-up will be documented in a supplemental report.