It's a grainy, jittery 44-second mobile-phone video, with the Blue Danube Waltz in the background.

And it's suddenly relevant because that master of publicity, Tesla Motors CEO Elon Musk, tweeted that the Model S "floats well enough to turn it into a boat for short periods of time."

It shows a Tesla Model S luxury electric car driving into a flooded underpass and halting, with numerous conventional cars and a truck seemingly stalled and water gushing out of a wall drain into the roadway.

DON'T MISS: Do Electric Cars Make You Worry About Toasters in Bathtubs? (Jul 2010)

After about 10 seconds, the driver decides to go for it, and powers through the most flooded part, with a bow wave actually breaking over the hood at one point.

Much of the phone video shows both the view out the windshield and the rear camera view of wake and waves astern.

How did the intrepid driver manage to make it though?

According to Musk, wheel rotation provides enough thrust to give a floating Model S forward propulsion.

"We definitely don't recommend this," he notes.

ALSO SEE: Tesla now building 2,000 electric cars a week, it says

The electric motors and battery pack of a Tesla are completely sealed, he added in response to a flurry of follower questions via tweet.

Indeed, perhaps haunted by the toaster-in-a-bathtub image, most electric cars are put through the same water tests as other vehicles from experienced carmakers.

Amphicar

Amphicar

As it turned out, one of the reasons that 16 Fisker Karma luxury plug-in hybrid sedans waiting in port in New Jersey caught fire and burned to the ground during the 2012 Hurricane Sandy was the lack of what's called a submersion test.

The fire spread to adjacent cars as well; overall Fisker lost more than 300 cars stored at Port Newark.

In that case, the cars hadn't been entirely submerged in water—which, in the event, led to a short in a Vehicle Control Unit due to salt damage. It caught fire when the Karma's 12-Volt battery fed current into it after everything dried out.

CHECK OUT: Sandy Carnage: Fisker Karmas Submerged In Salt Water Burn At Port (Oct 2012)

Back to the "floating" Tesla: as Musk suggests, don't try this at home, kids.

At least not if your Tesla is still under factory warranty protection. Tesla's known for great service, but emulating an Amphicar may not be covered.

And as an anti-Tesla reader points out, "Flooding of the Battery" is expressly not covered under Tesla's North American "Battery Limited Warranty."

[hat tip: Randall Hamlet]

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