Hydrofoil Boats (Everything You Need to Know)

Despite the technology being around for over a hundred years, hydrofoil boats have once again become a hot topic amongst boat enthusiasts. Hydrofoil technology enhances both speed and efficiency of water vessels, and has been used by US Navy watercrafts, superyachts, racing boats, ferries, and many more.

A hydrofoil boat is supported by a winglike structure that creates lift as the boat’s speed increases. This makes the boat faster and smoother by reducing drag and keeping the boat above the waves.

With hydrofoil boats making headlines once again, it’s time to go over what they are, how they work, their advantages, disadvantages, and a serious evaluation on whether they are the future of boating or not. In this article, we’ll go over all there is to know about hydrofoils.

What is a Hydrofoil Boat?

Photo Credit: candela.com

A hydrofoil boat is supported by a “hydrofoil” which is a structure composed of either a wing (V), T, or U shape. There are two types of hydrofoil boats: surface-piercing, and fully submerged. Both types of hydrofoils achieve the same purpose of lifting the boat off the surface of the water at high speeds.

When going fast enough, the lift of the foils is great enough to lift the entire hull of the boat out of the water, so that nothing but the foils themselves are touching the surface. This has some incredible benefits in terms of speed, efficiency, and experience – all of which we will soon go over.

Hydro foils help minimize drag and improve speed which is very similar to the effects achieved by aerofoils used on airplanes.

Hydrofoil boats are powered mainly in the same way other power boats are, by propellers or water jets. With that being said, they are also really popular in sailing. But the use of hydrofoils on sailboats is highly technical and primarily used by racing teams. They are most commonly used by commercial boats, and now are being introduced at the consumer level with pleasure boats.

History of the Hydrofoil Boat

The hydrofoil technology was first developed by inventors Casey Baldwin, Enrico Forlanini, and Alexander Graham Bell – yep, the same guy who invented the telephone. Forlanini had a prototype operating on Lake Maggiore in Italy by 1909. The hydrofoil boat achieved fame in WWII when it was used by both the German and US Navy to navigate waters that were heavily guarded by mines.

During the 1960s, 70s, and 80s, the hydrofoil technology was taken to water sports, where it was used in kiteboards, surfboards, and the air chair. It returned to the consumers’ attention in the 2010s, when it was used by racing teams across the world to set speed and time records in sailing championships. Most recently, watercraft companies have begun experimenting with the idea of hydrofoils on smaller scale boats outfitted with propelled and outboard engines.

How does a Hydrofoil Boat work?

So, we know that hydrofoils help boats achieve higher speeds with less drag, but how does that really work? The best way to think of it would be as “a boat with wings,” as that is essentially what they are. Just like an airplane would lift off the ground or water, as a hydrofoil boat gains speed, it lifts off the water too. While the foils themselves are submerged in the water still, much of the time there is enough lift to hold the entire hull of large ships and ferries off the surface. The sensation of being in a hydrofoil boat is much like being in an airplane that has limited flight. It’s smooth, and it’s really fast.

At the consumer level, hydrofoils require additional technology. As we’ll go over later on, this can result in some expensive price tags. As you can imagine, a boat that essentially “flies” through the air comes with some safety hazards. Hydrofoils require an automatic control system that maintains flying height, foil pitch, and smoothness of the ride. This “autopilot” system allows the foil to move in and out of the water safely, preventing the boat from slamming back into the water after it’s been lifted off the surface.

Hydrofoil Boat Advantages and Disadvantages

Their speed and unique ability to shed drag is undeniable, but are hydrofoils really all they are cracked up to be? In this regard, there are several advantages and disadvantages to consider.

Hydrofoil Advantages

  1. Speed: No surprise here. Most hydrofoils whether in the form of sailboat, ferry, or commercial vessel, can “fly” at speeds well over 50 knots (60 mph).
  2. Comfort: Because the hull of the boat is off the water, most waves and wakes hardly impact the boat, and therefore go largely unfelt by passengers. This makes for one smooth ride.
  3. Stabilization: For the same reason that comfort is increased, so is the boats stability (at high speeds that is). The hydrofoils cut through the water, decreasing the motion index of the watercraft.
  4. Efficiency: Since they aren’t impacted by smaller waves and wakes that would slow the progress of most boats, hydrofoils reach their destination in a much more efficient manner. For boats powered by traditional propeller or jet engines, this efficiency promotes a substantially better fuel economy.
  5. Experience: The reduced drag and impact from waves makes for a one-of-a-kind boating experience. It truly does feel like you are “flying” just above the surface of the water.

Hydrofoil Disadvantages

  1. Skill: Operation of a hydrofoil is a lot more technical, and requires a much more advanced skillset when compared to that of a standard runabout boat.
  2. Water Type: Hydrofoils are only suited for the open sea or large lakes (as of now). They are NOT fit for shallow water, as any bottom strikes while in motion could prove to be catastrophic for both the riders and the boat itself.
  3. Speed Range: Hydrofoils are built to “fly,” but only at certain speeds. Each boat will have a speed range where it likes to operate. Anything below that range will result in extra drag because the hull and the foils are submerged in the water. Anything above the range gets to be dangerous and uncontrollable.
  4. Maintenance Costs: The more complex technology comes with more complex maintenance and storage.
  5. Total Cost: They aren’t cheap. Some of the more popular boats at the consumer level cost upwards of $300,000.

While they may prove to be more complicated in terms of where you can drive them and their cost, there is an undeniable “coolness” factor with hydrofoil boats. As they gain popularity around the world, industry experts believe their cost and availability will become more and more accessible.

Hydrofoil Boat Costs

While you can find hydrofoils in nearly every style of boat, in this article we will cover the most common types of “personal” watercraft. You can find more information on commercial hydrofoils through this article by ScienceDirect.

  1. Candela C-8: Marketed as the ultimate “flying” watercraft, this electric jet powered hydrofoil is quickly making a name for itself as the best watercraft option across Europe. Candela is the industry leader in electric hydrofoils. Their electric C-8 outsells almost every internal combustion engine boat in its premium category.
    1. Price: $329,000
    1. Power Specs: 67 hp, 44 kWh battery, capable of cruising at 20-30 knots.

** One important sidenote to make about the C-8 is the incredible C-POD electric motor, which requires much less energy than a traditional internal combustion engine. The manufacturer promises 4,000 hours without any maintenance. That’s nearly 20 years of consistent use without maintenance!

  • Enata Foiler: This luxury hydrofoil is everything a superyacht should be. Supported by a sleek set of red winged hydrofoils, this futuristic watercraft rests at 4 feet above the waters surface when cruising. It’s arguably the smoothest ride on the market, even across high seas. But you pay the price for it.
    • Price: $900,000 (base price)
    • Power Specs: 740 hp supported by twin V8s, providing for cruise speeds upwards of 40 knots.
  • Candela C-7: The prelude to the C-8 comes with almost as much power, but at a cheaper price. Supported by an electric propulsion system and automatically actuating hydrofoils, this has become one of the most popular hydrofoil boats on the market.
    • Price: $240,000
    • Power Specs: 40 hp, 40 kWh battery, capable of cruising at 22 knots

** For a more in-depth review, check out this Youtube video:

The Future of Boating?

There are some undeniable advantages that hydrofoils have over general powerboats. The lift they get off the water not only makes for less drag and more speed, but also promotes a more comfortable and efficient ride. With that being said, their cost in manufacturing and maintenance has made them more costly than most people can afford.

It’s hard to say whether or not hydrofoils will be more commonplace at the consumer level. Right now, they are really just a fun toy for the wealthy. There are also some operational issues that manufacturers need to overcome before you’ll see them on your local waterway. Their susceptibility to damage in shallow water makes them unfit for anything but a large lake or open sea. Hydrofoils may not be as common as your run of the mill jet boat yet, but their popularity is growing at a rapid pace. If your local water happens to be a giant lake or open ocean, don’t be surprised if you start seeing more of them!