The Tesla Model S can double as a boat, according to Tesla CEO Elon Musk. “We def don’t recommend this, but Model S floats well enough to turn it into a boat for short periods of time,” Musk wrote in a Tweet over the weekend. “Thrust via wheel rotation.” “If curious abt TSWLM car,” he added a day later on Twitter, “am still planning to do a sports sub car that can drive on roads. Just a side project. Limited market potential :).” The “TSWLM” in this case stands for “The Spy Who Loved Me,” a James Bond film in which 007 drives underwater in a Lotus Espirit S1 that doubles as a submersible. In 2012, Musk purchased the automobile-submarine used in the film, and suggested he would figure out how to make it run. It’s difficult to tell if the second Tweet is an example of Musk’s dry sense of humor, or if he really intends to build a limited-production vehicle that can move beneath the waves like a shark. Then again, a decade ago, even the idea of a self-driving electric car would have seemed ludicrous—yet that concept is now a reality. Musk’s initial Tweet came in response to a video from Kazakhstan in which a Tesla driver piloted his vehicle through a flooded tunnel, weaving past internal-combustion automobiles trapped in the bumper-deep water. Although electronics and water generally don’t mix, it seems that the Tesla Model S’s internal components are sealed enough to permit the vehicle’s limited immersion. As competition in the electric-car space heats up, with Apple reportedly planning to issue its own four-wheeler at some point in the next few years, Tesla will almost certainly add lots of new features and styling in order to keep its cars appealing. Chances are pretty good, however, that Tesla vehicles’ future editions won’t tout possible seaworthiness as a primary perk.