Survivors of a deadly tour boat accident in the Adirondacks dispute the captain's claims that a large wave was to blame, and claim the boat may have been carrying too much water and too many people, according to documents released Friday.

The National Transportation Safety Board released reams of testimony and evidence gathered in their probe of the sinking of the 40-foot Ethan Allen on a calm day on Lake George last Oct. 2, killing 20 people.

The 40-foot boat was carrying 47 passengers plus the ship's captain when it capsized in calm weather. The passengers were elderly tourists from Michigan and Ohio on a fall foliage trip.

"When you get on a boat that's half full of water, it acts very sluggish and unstable about the roll axis," survivor Joseph Mahalak told the NTSB. "The boat that we were on, the Ethan Allen, acted to me like it had a lot of water in the bilge."

Tests on the boat's equipment may explain why Mahalak, a retired engineer, worried about water inside the ship.

Investigators re-created the action of the coolant pump, designed to maintain proper engine temperature with water from the lake.

The pump recovered from the boat did not appear to be tightly attached, and under testing conditions, leaked as much as a gallon of water every five minutes, according to NTSB documents.

But the same testing suggested the gap, less than a tenth of an inch, may not have existed at the time the ship sank, because in testing the engine ran only about four minutes before it overheated, and the Ethan Allen had been running for much longer.