"Based on the information and data known at this time, the Sheriff's Office is declining to file criminal charges and is referring this matter to the District Attorney's office," Warren County Sheriff Larry Cleveland wrote.
Investigators examined whether there was intentional, reckless or negligent criminal culpability by the boat's owners or operators. Cleveland said it was up to the state and federal governments to recommended changes in safety rules.
A call to Warren County District Attorney Kate Hogan was not immediately returned Friday.
The 530-page report includes statements from victims and other witnesses.
Carol Charlton, tour director for Shoreline Tours of Canada, which arranged the Oct. 2 trip, told investigators her group was supposed to be 50 people, but after a discussion with the boat's pilot and another captain, two heavyset women decided not to go.
Charlton said that when she sat in the boat, its sides "were very close to the water."
"The boat left and we had been going about a half an hour when the pilot suddenly made an extremely sharp turn to the left," Charlton said. "When he made the turn, it was so violent that I slid to the floor and realized the boat was overturning. I remember getting a wiff (sic) of diesel smoke or something and then I was in the black water and knew I was under boat."
The 40-foot Ethan Allen overturned suddenly, throwing the captain and 47 passengers, most of them elderly tourists, into Lake George.
The weight the boat was carrying and how that weight was distributed emerged early as possible causes of the accident. The boat was certified for up to 50 people, but officials say that was based on obsolete weight guidelines.
The National Transportation Safety Board has yet to issue its final report, but it said in early January it was examining the boat's engine, coolant pump and canopy. According to the NTSB, a larger engine, heavier canopy and more ballast were added to the Ethan Allen after it was built in 1964.
Lawsuits have been filed in federal court in Michigan and New York alleging negligence by tour boat company Shoreline Cruise Inc. and the boat's pilot, claiming that there should have been another crew member aboard, life vests should have been accessible, the boat was flawed and overcrowded. Most of the victims were from Michigan.
Shoreline Cruises has said the Ethan Allen was in compliance with all state guidelines regarding passenger limits at the time of the accident.