What exactly was Mark Zuckerberg riding in that viral Fourth of July video?

If you’ve been scrolling around on social media this month, then you may have noticed that over the Fourth of July weekend, Facebook creator Mark Zuckerberg was riding on some sort of wakeboard on a lake with an American flag in tow.

Zuckerberg, who isn’t particularly well-known for doing anything remotely physical or extreme, looked very at ease riding the machine, which looks like a cross between a wakeboard and a hoverboard. It straight up looks like something out of an action movie.

The video was oddly finished with John Denver’s “Take Me Home, Country Roads,” because what else is more American than riding a hoverboard over a large body of water carrying an American flag and jamming to John Denver, right?

While the video will forever be a giant mystery, it did get us thinking: What exactly was Zuckerberg riding?

After doing some internet searching, we found out that whatever Zuckerberg was doing is an actual thing called hydrofoiling, something that is becoming popular with outdoor enthusiasts, apparently.

It’s kind of like a cross between riding a wakeboard off the back of a boat and surfing.

Underneath the board are fins shaped like an airplane that give the board lift when in motion.

There are electric boards that produce momentum, but you can also propel yourself by shifting your weight from the front of the board to the back if you’re in flat water. It’s kind of like you’re pumping, but with your legs.

The most fun way to hydrofoil is by riding a wave, which is what Zuckerberg was doing in his video. It looks like he was filmed from a boat, and he was using the momentum from the wake of the boat to ride it and gain speed.

Even big boats and catamarans use a hydrofoil to travel in the water, so it’s not something that is super new. It is, however, new for people to see them used in a fun, recreational way.

Check out the video below of someone riding the giant waves in Hawaii.

Of course, the equipment you need in order to hydrofoil is insanely expensive, so don’t be too shocked if you never see one of these things out on the lake this summer. But perhaps in a few years, they might become popular.

While Zuckerberg looked just a tad awkward riding his board for his Fourth of July salute (it’s the thought that counts, right?), this does look like something that is really, really fun.

Perhaps he’s been learning this new sport to take his mind from the book “The Ugly Truth” that’s coming out soon, that’s all about him? Either way, it looks like he was having a great time.