On 1 November 2020, PADI Open Water Diver Linnea Rose Mills[1] drowned during a training dive in Lake McDonald in Glacier National Park, Montana, while using an unfamiliar and defective equipment configuration, with excessive weights, no functional dry suit inflation mechanism, and a buoyancy compensator too small to support the weights, which were not configured to be ditched in an emergency.[2][3] She had never been trained or even given a basic orientation in the use of a dry suit. This defective equipment configuration was supplied by the dive school, and the instructor, who was registered but had not been assessed as competent to train dry suit diving, did not take appropriate action compliant with PADI training standards or general recreational diving best practice, at several stages of the dive.[3]
During the dive, her dry suit was compressed by the ambient pressure, and as she was unable to add gas to restore buoyancy, she became negatively buoyant and was unable to swim upwards, further hindered by suit squeeze. She fell off an underwater ledge while trying to attract the attention of the instructor, and though a fellow diver attempted to stop her descent, he was unable to ditch any of her weights and had to surface to save himself.
The incident was poorly investigated and as of November 2024, no criminal charges have been made, but a civil case for $12 million was eventually settled out of court, and counsel for the plaintiffs has urged the state to prosecute. The Professional Association of Diving Instructors was alleged to have failed in their duty of care by not providing sufficient quality assurance oversight on the dive school and instructor, and by setting standards for training that were ambiguous and in places contradictory, relying on interpretation by the service provider, which allowed plausible deniability of responsibility by PADI if an accident occurred.[3]