CORNISH, N.H. – The family of a woman who drowned on a rescue boat last summer has sued three towns, several rescue agencies and an air boat manufacturer, saying the woman’s death was preventable.

The state already held an investigation into the drowning. While it found that the placement of weight on the boat was a factor in the accident, criminal charges were not filed.

Virginia Yates, 64, died on Aug. 22, 2006, when the boat to which she was strapped sank in the Connecticut River. She was being transported from a dock where she had tripped and injured her ankle.

The lawsuit targets nine groups, including the Cornish Rescue Squad; the towns of Charlestown, Cornish and Plainfield; and the company that made the boat, Maine Yankee Airboat in Sebago, Maine.

The Cornish Rescue Squad recently had bought the air boat used in the rescue. In the lawsuit, the family accuses the squad of negligence, saying that Yates “was not provided with a life jacket or any other flotation device” and that “Virginia Yates was effectively lashed to the boat.”

The lawsuit said that the air boat was overloaded when it took on water and sank, and that “the Cornish Rescue crew members were novices who undertook the mission with inadequate training and without any apparent awareness of the boat’s design limitations.”

Most of the counts listed in the lawsuit were against the Sebago company that made the boat. The lawsuit stated that the manufacturer gave Cornish Rescue two hours of training, and that the air boat should have been used only in water less than 2 feet deep.