A report detailing the cause of a fatal high-performance boat accident on Lake Lanier in July that claimed the lives of two married couples has been released by the Georgia Department of Natural Resources.

"Excessive speed" and "careless/reckless” were the first and second contributing factors, respectively, in the July 15 single-boat crash, which the DNR categorized as a capsizing, that took the lives of the boat’s operator, Arthur J. McMahan, 46, his wife, Melissa Renee McMahan, 45, and two passengers, Anthony J. and Tammy R. Reece, 45 and 44, respectively.

The accident occurred near Cocktail Cove and Lake Lanier Islands in Hall County, when, according to a final Critical Incident Reconstruction Team’s report, McMahan’s 38-foot 2009 Skater fiberglass motorboat attempted to overtake a boat and crossed its wake.

“Due to the high rate of speed [McMahan’s boat] was traveling, the bow lifted into the air and [it] became airborne,” the report said. “[It] fell back into the water on its port stern sponson first. The starboard sponson then came down and the vessel began to bounce starboard to port.”

According to witnesses statements recorded in the DNR report, that was the moment when the occupants were ejected from the boat.

Witnesses reported at the time that the vessels were traveling between 100 and 130 miles per hour.

“The impact with the water at speeds exceeding 100 miles per hour likely caused instant death to the victims,” the report said.

In the main narrative, Cpl. Wil Smith, of the DNR’s Law Enforcement Division, said speed was a “major contributing factor in this incident … proper use of personal flotation devices could have helped the survivability of the victims.”

The McMahans were from Mt. Washington, Kentucky, and the Reeces were from Columbia, Kentucky.

The two women’s bodies were found between 3 and 6 a.m. July 16 by units with a sonar boat, and the two men’s bodies were recovered July 17 between midnight and 1:30 a.m.

Law enforcement personnel from Forsyth County, the DNR, Hall County and the Army Corps of Engineers responded to the scene in July, which occurred the night before the Lake Lanier Pirates Charity Poker Run, a weekend where boats follow a path around the lake picking up large playing cards.

The cards are used later at Sunset Cove in Lake Lanier Islands to play poker against other boats, and extra money benefits charities.

The event began with a “memorial run” procession of boats from the Buford Dam to the Gainesville Marina.