Though the exact vehicles may vary from city to city, duck boats are often refurbished DUKW vehicles used by the United States military and its allies throughout the mid-20th century. Built by General Motors, the DUKW vehicles were first deployed during World War II to transport military supplies from ships to the coast without requiring the ships to dock.
With the push of a lever, the vehicles switched from being wheel-operated to being powered by a rear-mounted propeller, and the driver steered both the wheels and the rudder using the same system. The DUKW vehicles also came equipped with a system that allowed the driver to adjust the inflation level of the tires for better flotation or tire traction.
The vehicles reportedly allowed Allied forces to move more than 3 million tons of troops and equipment around the European theater during World War II.
General Motors built more than 21,000 DUKW vehicles during World War II. Though some of them remained in military service until the 1960s, many eventually ended up with local law enforcement agencies or private tour companies.
Original Wisconsin Ducks in Wisconsin Dells, Wisc., claims to have launched the first duck tour in 1946. Duck tours utilizing refurbished DUKW vehicles have since popped up in cities around the world.
In many cities, duck tours are independently owned and operated, often under branding like "Ride the Ducks" or "Duck Tours." Many tour companies hand out signature yellow duck lip whistles to customers wishing to quack along during the tour.
Some safety advocates have called the boats unsafe after several high-profile fatal accidents involving the vehicles over the course of the last two decades. In two accidents on the water, the boats either sank or capsized, killing more than a dozen passengers in each incident. The vehicles have also been involved in multiple fatal accidents on roadways.
"Duck boats are death traps," Andrew Duffy, an attorney whose Philadelphia law firm handled litigation related to fatal accidents involving duck boats, told the Associated Press. "They're not fit for water or land because they are half car and half boat."
Advocates claimed that different agencies have imposed varying safety requirements on the boats, the AP reported.