​About 1908 central daylight time on July 19, 2018, the Stretch Duck 7, a 33-foot-long, modified World War II-era DUKW amphibious passenger vessel that was operated by Ripley Entertainment Inc. dba Ride The Ducks Branson, sank during a storm with heavy winds that moved rapidly on Table Rock Lake near Branson, Missouri.[1] Of the 31 persons aboard, 17 fatalities resulted. Several hours prior to the accident, the National Weather Service had issued a severe thunderstorm watch for the area, followed by a severe thunderstorm warning a minute before the vessel departed the shoreside boarding facility—a roadside building about 6 miles away from the lake where the tours commenced and concluded. Due to the approaching weather, the manager-on-duty advised the captain and driver as passengers were boarding the vessel to complete the lake portion of the tour before the land tour (which normally occurred first). In addition, three other company vessels also began waterborne tours following the severe thunderstorm warning. About 5 minutes after the Stretch Duck 7 entered the water, the leading edge of a storm front, later determined to be a “derecho,” passed through the area generating strong winds and waves reportedly 3–5 feet high, with the highest wind gust recorded at 73 miles per hour (mph).[2] The Stretch Duck 54, which entered the lake about 2 minutes before the Stretch Duck 7 and was conducting a tour on the lake, was able to exit the water after experiencing the severe weather. During its effort to reach land, the Stretch Duck 7 took on water and sank approximately 250 feet away from the exit ramp. Several first responders, along with the crewmembers and passengers aboard a paddlewheeler moored nearby, rescued and triaged 14 passengers, 7 of whom were transported to a local hospital. Loss of the vessel was estimated at $184,000. Investigators retrieved and reviewed audio and video data from the vessel’s digital video recorder system, which provided first-hand observation of the circumstances leading up to the accident.

1. ​A DUKW (pronounced “duck”) was an amphibious landing craft used to transport military personnel and cargo. The acronym signifies the characteristics of the vessel: D=1942 (the year of design), U=utility, K=all-wheel drive, and W=dual powered rear axles. The Stretch Duck 7 was originally built in 1944.
   
2. Pronounced “deh-REY-cho,” this widespread, long-lasting windstorm is associated with a continuous band of rapidly moving showers or intense thunderstorms and is characterized by a rapid increase of damaging, strong winds.

The probable cause of the sinking of the amphibious passenger vessel Stretch Duck 7 was Ripley Entertainment Inc. dba Ride The Ducks Branson’s continued operation of waterborne tours after a severe thunderstorm warning was issued for Table Rock Lake, exposing the vessel to a derecho, which resulted in waves flooding through a non-weathertight air intake hatch on the bow. Contributing to the sinking was the Coast Guard’s failure to require sufficient reserve buoyancy in amphibious vessels. Contributing to the loss of life was the Coast Guard’s ineffective action to address emergency egress on amphibious passenger vessels with fixed canopies, such as the Stretch Duck 7, which impeded passenger escape.​

​​To the US Coast Guard

• Require that amphibious passenger vessels equipped with forward hatches enable operators to securely close them during waterborne operations to prevent water ingress. (M-20-1)
• Review the circumstances of the Stretch Duck 7 sinking and other amphibious passenger vessel accidents, and revise Navigation and Vessel Inspection Circular (NVIC) 1-01 to address the issues found in these accidents, including operations during imminent severe weather and emergency egress during rapid sinking. (M-20-2)
• Examine existing training and knowledge requirements for understanding and applying fundamental weather principles to waterborne operations for Coast Guard-credentialed masters who operate small passenger vessels; and, if warranted, require additional training requirements for these ratings on recognition of critical weather situations in pre-departure planning and while under way. (M-20-3)

To Ripley Entertainment Inc., dba Ride The Ducks Branson

• Using the operating restrictions found in vessel certificates of inspection, review and revise your current operating policy to provide specific guidance on vessel operations when adverse conditions could be encountered during any part of the waterborne tour by implementing a go/no-go policy. (M-20-4)
• Modify spring-loaded forward hatches of modified DUKW amphibious passenger vessels to enable their closure during waterborne operations as a prevention for water ingress. (M-20-5)
• Re-evaluate emergency procedures regarding the donning of lifejackets aboard modified DUKW amphibious passenger vessels when equipped with fixed canopies. (M-20-6)  ​