How eFoils Work — Electric Flying Surfboard Explained!

Have you seen a couple of videos on the Lift eFoil, or people on a lake or ocean nearby flying on an electric surfboard? Or maybe you might have seen Mark Zuckerburg in the news or social media waving the American Flag while riding, or when he had his face covered in sunscreen on his eFoil. The technology behind what’s actually going on here is incredibly impressive, but there’s also a lot of science and history behind it as well that dates all the way back to the late 1800’s.

In this artcile, we’re going to answer the question: what is an eFoil and how does it work? We explain how to actually get flying above the water on one of these boards and the difference between the battery powered eFoil, and the non motorized surfing ones.

What is a eFoil — How Does It Work?

First off — what exactly is a hydrofoil? Well, there are two different types — a surface piercing hydrofoil and a fully submerged hydrofoil, but both achieve the same effect — lifting the hull of a watercraft out of the water to fly above the waterline.

This isn’t a new concept — people have been toying with the idea since 1869, when British patents were found with “wedge form pieces” adapted to a boat model to effectively lift the vessel and reduce drag. Later, in 1919, Alexander Graham Bell (yes, the same guy that invented the telephone) successfully designed a hydrofoil boat and broke a world speed record of 70.85mph.

And for a while after that, hydrofoils became tools for the military to hover the waters. But more recently, surfers have taken it upon themselves to use the science and technology for fun.

So what is the science behind achieving flight and feeling like Jesus on one of these boards? Much of it is based on Bernoulli’s Principle: if fluid’s speed increases, it’s pressure decreases. Taking a look at our fully submerged foil wing under the water, you’ll notice that it resembles a small plane — and that’s because a hydrofoil achieves lift, very similarly to how a plane achieves lift.

As you cut through the water and start to pick up speed, the pressure on the top of the wing decreases, as the pressure under the wing increases — This, along with the way the wing is shaped — effectively creates lift.

An eFoil next to a plane to show how the wings work in the same way as an airplane

Now, similar to how a plane stays in the air — using a mix of this principle and its engines to create horizontal thrust — a hydrofoil craft also needs some sort of horizontal thrust to lift and stay lifted.

Hydrofoil vs eFoil

This is where we jump into the difference between a regular foil — like the one Zuckerburg rocked on July 4th — and an efoil, a hydrofoil board geared up with a battery and propeller.

Lift eFoil, motorized hydrofoil

Both types can get you lifted and flying over the water, but regular foils are obviously a bit more simple in design — they’re composed of the board itself, a mast submerging into the water, and the foil wing. But without a motor to propel it forward, surfers who hop on foil boards need to find other ways to get horizontal thrust.

Many times, regular foilers learn to paddle into a wave, surf it and using the momentum along with pumping motions, can turn all the way back around and catch a second wave. The advantage of foiling is there’s a lot less drag and resistance, and the wing under the water can ride much smaller swell, the type of rolling waves you see out in the distance before they crash.

An easier type of foiling is to get towed behind a boat or a jetski, so you can ride the wake or get pulled into a wave. A harder way to foil is using a kite sail or even a kite wing, which is for more advanced riders already into kite sports. Pro riders such as Kai Lenny are doing all sorts of tricks like backflips and 360’s on foils.

Kai Lenny doing a backflip on a regular foil

How an eFoil Is Made

But looking at the eFoil, this is an entirely new product invented from the ground up. It’s built by Nick Leason and his team at Lift Foils, who have been making regular surf foils for a long time before the eFoil. We’re familiar with Lift and the eFoil, being an early adopter of the 1st version in 2018. We now have 2 of their boards and ride them every summer in both freshwater lakes and oceans.

Photos from Lift factory in Puerto Rico, where eFoils are hand crafted

The eFoil is composed of the board, mast and wing- all built of full carbon fiber for maximum durability. Inside the board, the electronics and computer are housed in another waterproof casing, which even has water cooling that’s piped down all the way from the motor. There’s a big space for the battery, which is a massive 2.1 kwh battery that weighs 29 lbs. The charger for the battery is also big, plugs into a regular wall outlet and can charge the battery in under 2 hours.

Controlling the eFoil, you use a remote controller that wraps around your hand and has a trigger to control the motor speed. The only thing the remote controls is the speed, all other movements like turning and getting lift are controlled by your body and feet.

The motor on the eFoil is located on the bottom, right above the wing. This provides the horizontal thrust to the wing and mast, and causes the wing to want to immediately go up. By putting extra weight on the nose of the board, the rider keeps the board down to continue gaining more speed, until the board is level and riding flat on the water. With enough speed, an eFoil rider can now start to Lift up and ride only on the wing, while controlling the left, right and up/down movements with their body and feet.

The amazing part of the eFoil is that the motor allows riders to quickly learn and experience the sport of foiling. Just about anyone can learn to eFoil, from young to old. There are riders as young as 6 years old, and others in their 60’s and 70’s. Most beginners can learn and begin Lifting in their first lesson of riding, regardless of having any board sport experience at all.

A beginner getting Lift their 1st time riding

And once you’ve tried it, you’re hooked, ready for your next turn to get back out there. The feeling you get when riding an eFoil can only be described as magical, unleashing a type of feeling felt in your body and mind. You start to feel the wing that’s gliding underneath the water, both in your feet and legs. Since the board is electric it barely makes any noise, leaving you to hear all of the natural sounds and water splashes around you. When riding in crystal clear water, you can see the fish and other wildlife swimming around you. And when riding with others, you can easily talk and hear each other.

And the possibilities of how and where you ride an eFoil are endless, since you don’t need any waves to ride. You can also swap out wings from small to big, where smaller wings allow you to go fast and cut through the water, while much larger wings provide more lift and a more stable ride to allow you to foil even at slower speeds.

Lift even makes different propellers like a folding prop, so more advanced riders can use the motor to get into swell, and then cut the motor so the prop folds in half and reduces the drag when riding the wave.

Price and Where To Buy

Looking at the price, you can buy a non-motorized Foil board from different companies and at a minimum you’ll spend around $1,300 for a complete setup. And it can go up to $2 to $3,000 depending on material and wings you buy.

For the eFoil, get ready for sticker shock — with the price coming starting at $10,000 for the Lift 3 F. But there’s a good reason for it, with components to build it being extremely expensive. You also need quality engineering to make sure the board won’t come apart or break in the water. In a nutshell, the eFoil is basically a Tesla of watersports.

The different sizes available for the Lift eFoil

If you’re interested in learning more about the eFoil, the invention and construction of the board, be sure to check out our podcast with Nick from Lift, and watch our other videos of all the Lift boards and accessories that we’ve reviewed.