The duck boat involved in the fatal accident that killed 17 people when it overturned in Branson, Missouri, was not supposed to operate in water if winds in the area clocked in at 35 mph or waves were higher than 2 feet, according to the vessel's certificate of inspection, released by the U.S. Coast Guard.
"Vessel shall not be operated waterborne when winds exceed thirty-five (35) miles per hour, and/or the wave height exceeds two (2) feet," the certificate, filed on Feb. 7, 2017, states.
On the night of July 19, winds on the Table Rock Lake hit 73 mph, and the wave were higher than 3 feet, officials said. The boat, which had 31 people on board, overturned and sank after it was capsized by the waves, officials said.
It is unclear what the wind speeds and wave measurements on the lake were when the duck boat entered the water.
(MORE: $100 million suit aims to 'drive death-trap duck boats out of business': Lawyer)The National Weather Service outpost in Springfield, Missouri, had issued a Severe Thunderstorm Warning for the area that night, predicting winds of up to 60 miles per hour and penny-sized hail.
As the passengers were loading, the captain made a verbal reference to looking at the weather radar prior to the trip, an NTSB report stated.
(MORE: Duck boat captain checked weather, discussed life jackets before sinking: NTSB report)Earlier this week, a $100 million federal lawsuit was filed in Kansas City, Missouri, Sunday night by lawyers representing victims of the Indiana family that lost nine relatives, including four children, in the accident.
Named as defendants are Ripley Entertainment, the owner of the Ride the Ducks operation in Branson, and Ride the Ducks International, which sold its duck boat fleet to Ripley in 2017.
The lawsuit alleges that the duck boat operators were negligent in not heeding weather advisories of an impending storm.
(MORE: Last photo shows happy family before duck boat horror left 9 of them dead)An NTSB report released after the accident stated that the boat's captain checked the weather reports and discussed safety procedures, including the location of the life jackets as passengers boarded the vessel.
The federal lawsuit also alleges that operators changed the route of the 70-minute tour from land to the water in hopes of beating the bad weather forecast.
In a statement, Suzanne Smagala, public relations manager for Ripley Entertainment Inc., said that the company is "deeply saddened by the tragic accident" but that no conclusions will be made until the NTSB investigation is complete.
"We remain deeply saddened by the tragic accident that occurred in Branson and we are supportive of the affected families," she said. "The investigation by the National Transportation Safety Board is still underway and no conclusions have been reached. We cannot comment at this time."
Duck boats have killed a total of 42 people over the past two decades, Robert Mongeluzzi, the attorney for the Coleman family, said at a press conference Monday in Kansas City, adding that the companies within the industry have ignored repeated warnings that the vessels are dangerous on both water and land.
The U.S. Coast Guard has convened a formal Marine Board Investigation into the duck boat incident, the highest level of investigation in the Coast Guard, the agency announced in a press release Wednesday.