NTSB Says Failure to Heed Weather Warning Led to Fatal Sinking of Duck Boat
The World War II-era amphibious duck boat sank July 19, 2018 during a strong thunderstorm on Table Rock Lake near Branson, Missouri, killing one crew member and 16 passengers.
The Stretch Duck 7 was operated by Ripley Entertainment Inc., aka Ride The Ducks of Branson.
The findings of the NTSB’s investigation were released Tuesday during a virtual public board meeting.
“Ride the Ducks of Branson continued to operate waterborne tours after a severe thunderstorm warning had been issued. This exposed the vessel to a derecho, which resulted in waves flooding through a non-weathertight air intake hatch on the bow, which caused the vessel to sink,” the NTSB determined.
In their investigation, NTSB investigators documented that the National Weather Service had issued a severe thunderstorm watch for the area several hours before the sinking. The forecast was updated to a severe thunderstorm warning one minute before Stretch Duck 7 departed the shoreside boarding area, located about 6 miles from the lake. Investigators noted three other company vessels also entered the lake after the severe thunderstorm warning was issued.
“Had Ride The Ducks employees taken more appropriate actions and made better decisions, it is likely the duck boat would not have sunk, because they would not have continued operations based on the weather forecast and prevailing conditions,” said NTSB Chairman Robert Sumwalt.
The NTSB also cited U.S. Coast Guard’s failure to require sufficient reserve buoyancy in amphibious vessels as contributing to the accident. The NTSB investigators found that the duck boat was originally constructed with a low freeboard, an open hull, and no subdivision or flotation, resulting in a design without adequate reserve buoyancy.
The NTSB noted previous inaction to address emergency egress on amphibious passenger vessels with fixed canopies which impeded passenger escape from the Stretch Duck 7. Both reserve buoyancy and improved emergency egress, including the fixed canopies, were the subject of a NTSB Marine Safety Recommendation issued in November 2019.
The NTSB said the fixed canopy of the Stretch Duck 7 contributed to the severity of the accident. When the vessel sank, the closed starboard-side curtain aboard the vessel impeded the passengers’ escape and likely resulted in additional fatalities, the NTSB concluded.
The NTSB has issued six safety recommendations with three recommendations issued to the Stretch Duck 7’s operator and three recommendations to the U.S. Coast Guard addressing safety issues including company oversight, engine compartment ventilation closures, reserve buoyancy, survivability, weather training for mariners, and Coast Guard guidance.
Since the 1999 fatal accident involving the Miss Majestic DUKW, the NSTB has now issued a total of 28 safety recommendations related to modified WWII-era DUKW passenger vessels. Among the 22 previously issued, only nine had been implemented fully by the Coast Guard as of November 2019.
An abstract of the NTSB’s final report, which includes the findings, probable cause, and all safety recommendations, is available at https://go.usa.gov/xvEzG.
A final report for the investigation is expected to be published in the next few weeks.
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