The world's first driverless water taxi has been built in Tennessee

Sea robo-taxis are increasing urban mobility and reducing damage to the environment, while making it possible for the world's 99 percent experience the luxury of blissful water rides.

By Stav Dimitropoulos , written on March 2, 2021

From The Culture Desk

Α month ago Don Βutler hopped on board a modular pontoon boat with four other guys for a ride along the Knoxville side of the Tennessee river. It was a sweet day; cloudy, but balmy. The boat speed went up to four knots, and its passengers traveled for a total of ten minutes up the river, and then for another ten minutes back down to the marina.

The traveling group enjoyed a chit chat while marveling at the beautiful fall colors of Knoxville in the winter. Butler, who is the harbormaster for the port of Knoxville, has been on boat rides countless times. But this was unlike any other Tennessee trips of his. He would previously travel by boats manned by a crew of several people. But this one drove itself.

‘Greycraft’ was the world’s first autonomous water taxi.


Greycraft is a solar-powered, autonomous vessel driven by artificial intelligence 

It belongs to Buffalo Automation, a US-based developer of artificial intelligence (AI)-powered autonomous water transport. Buffalo Automation has created a predictive boat navigation system that guides large commercial ships and boats. The system uses supersmart AI, neural networks, and thermal imaging technologies to steer the boat through the water environment and identify safety risks and issue critical warnings. Greycraft features an easy to assemble and disassemble modular design. The solar panels powering it have a battery capacity of about six hours, and promise to remain functional for many years after deployment with no maintenance. 

“Exactly because it isn’t charged by electricity is the reason why Greycraft has great environmental benefits,” says Thiru Vikram, co-founding CEO of Buffalo Automation. “When you charge electric vehicles, there's always the question of where the electricity is coming from; maybe it's coming from coal plants,” Vikram says. Robotaxis are also distinguished by a very noiseless engine, which won’t disturb the peace and quiet of local marine life (the destructively disorienting watercraft noise causes strandings of whales and giant squids or even hemorrhages and damage to the internal organs of marine mammals). And unlike its gasoline-fuelled counterpart, a ghost taxi won’t drop oil particulates into the water. 


Water taxis are a low-cost way for the world to enjoy the pleasures that the world's one percent takes for granted

Autonomous water taxis are paving the way for future autonomous ferry and water taxi companies to serve the public, Vikrams confidently says. Through an app called Mayday, commuters can hail a water taxi, much like users call for a Lyft or Uber,  for less than $12. “They can go fishing, have dinner with their friends, socialize, and come back and that's your total cost for going out in the water. Compare that to paying, say $61,000 to buy a boat,” says Vikram. It is a low-cost way for anyone to somehow partake of one of the pleasures the world’s one percent takes for granted - you know, yacht life, bliss, and everything. 

"Autonomous ship applications have advanced rapidly because vessels on waterways have less potential conflicts to navigate than vehicles on roadways, especially city streets,” says Stan Caldwell, adjunct associate professor of transportation and public policy at Carnegie Mellon, and executive director of the university’s Traffic21 Institute.

Automated cars and trucks need to contend with each other and with pedestrians, so a waterway is definitely more flexible than roadways. This doesn’t mean water paths don’t have their own challenges though. “Potential conflicts would be debris in the water, shallow water, and other vessels, but even these are more limited than what you might encounter on a roadway,” says Caldwell. Docking and crossing are also good applications of marine self-driving robots. “Automation can enable precision docking with use of sensors as we have seen applied with automated buses,” Caldwell says.

It sounds an oxymoron that Caldwell’s major concern about these impressive robotic water taxis is related to the very reason why they were created in the first place: to ditch human drivers. Automated machines may be highly competent at repeating precision tasks that they have been programmed to do over and over again without getting bored or distracted, but they lack a virtue unique to humans: judgment, particularly in the face of the unknown. “Humans are superior using judgment in situations they have not encountered by applying past experience or common sense,” says Caldwell. Not having a human captain to gauge when water conditions are not safe can prove fatal, especially when water and weather conditions can change in less than a minute. Human supervision of the automated vessel is necessary, concludes Caldwell. 

When Butler jumped onto the self-driving modular pontoon in January 2021, he felt “exhilarated”. “The way that it operated was amazing. If something got in its way, it changed course automatically to avoid that object, and got right back on the course and kept going,” he remembers. 

Vikram is not that concerned about accidents; Greycraft is not meant to be particularly fast and unpredictable, capping five miles an hour, and covering routes lasting an average of thirty minutes. Most of all, he thinks this is a great opportunity for Knoxville--which belongs to Tennessee’s 2nd Congressional District, where 96 boating-related businesses recruit 1,965 people and support 745 indirect jobs, accounting to a total annual economic impact of $711 million--to shine nationwide and worldwide.


If robotic water taxis take off in Knoxville, the city will set an example for green urban mobility

Butler couldn’t agree more. During his many years of serving the city as a harbormaster, he has seen a fair share of mechanical boats polluting Tennessee. He is eager to see more companies substitute fossil fuels with alternative sources of energy. 

"The entire country, the entire planet should think like that. We should become more of a green planet. Why use a car when you can take a nice quiet ride down to downtown Knoxville, get off the boat, have dinner and socialize and do whatever you want, and then get back on the boat and go right back up to the point where you got on?” he wonders.

Apparently, a self-driving, “laid-back” water taxi might do all that, with less damage to the  environment, and with a twinge of luxury. 


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