Radio-controlled Gus class hovercraft
DIY-HOVERCRAFT.COM
Introduction to hovercrafts
This page features images that I did not create or own — sources are credited here.
To understand how hybrid a hovercraft really is, consider the three following points:
- Like a boat, it must float, handle waves, and deal with water currents
- Like an aircraft, it must be aerodynamic, lightweight, and precisely balanced
- Like a race car, it needs enough engine power to reach high speeds
This diagram illustrates how a single-propeller hovercraft operates.
The propeller generates airflow for both propulsion and lift (i.e., the air cushion or skirt).
A fixed deflector redirects part of this airflow beneath the craft. It’s this redirected stream of air that enables the hovercraft to “lift off” and hover above the ground.
The propeller generates airflow for both propulsion and lift (i.e., the air cushion or skirt).
A fixed deflector redirects part of this airflow beneath the craft. It’s this redirected stream of air that enables the hovercraft to “lift off” and hover above the ground.
Here’s how a “vented bag skirt” works in detail (note: the illustration does not show this exact type, but the principle is similar):
- Air fills the skirt, causing it to inflate.
- The air then flows through multiple openings toward the center of the hovercraft, lifting it completely off the ground.
- From there, the air escapes outward from underneath the craft, forming a thin layer of air between the skirt and the surface.
This thin cushion of air is essential for the hovercraft to glide. That’s why small vent openings must be included in the skirt. In our Formula 3 model, for example, these vents are located at the front and rear of the skirt.
Back in the 1960s, just as the Concorde symbolized the future of air travel, large hovercrafts were seen as the next evolution in maritime transport. Their speed and minimal infrastructure requirements made them strong contenders to replace traditional boats and ferries.
As illustrated by this picture of the French N500, hovercrafts only require a basic concrete ramp for loading and unloading passengers or cargo—far simpler and more cost-effective than conventional port facilities.
Unfortunately, iconic large hovercrafts were retired following the opening of the Channel Tunnel, for two main reasons:
- their high fuel consumption made them costly to operate — far more expensive than the trains now running beneath the Channel
- they were never mass-produced like airplanes or cars, which meant spare parts were extremely expensive
Smaller hovercrafts are still in use today, serving a variety of roles such as sea rescue, coastal patrol, short-distance passenger transport, navigating difficult terrain like swamps or polar regions—and even in racing.
On the military side, notable examples include the Zubr class, operated by Russia, China, and Greece, and the Griffon 2000TD, deployed by British and Peruvian special forces.
In general, the autonomy of hovercrafts is well-suited to small maritime areas such as the Aegean Sea. Greece, for instance, is one of the few countries able to fully exploit the tactical potential of its four Zubr-class hovercrafts, purchased from Russia and Ukraine.
Conversely, their limited range makes hovercrafts unsuitable for long-distance missions or for patrolling vast maritime zones, such as those overseen by countries like the United States or France.
In the 1970s, the British explored the idea of nuclear-powered hovercrafts—much like how nuclear propulsion had been adopted for submarines, civilian ships, and aircraft carriers. Such a design could have solved many of the hovercraft’s limitations: quieter engines, zero CO₂ emissions, and autonomy lasting up to 5 or 10 years.
However, unlike boats, which benefit from the buoyancy provided by water (thanks to Archimedes’ principle), hovercrafts would need significantly larger and more powerful lift turbines to carry the added weight of a nuclear reactor. This would reduce available space for passengers or cargo, making the concept difficult to implement.
Electric battery propulsion could be a more feasible alternative, but slow charging times and limited energy density would likely make the idea unappealing to commercial operators.
To dive deeper, there are several types of skirts—each with its own advantages and limitations :
A model of the French hovercraft SEDAM N500, fitted with a SEDAM bi-conical skirt—a configuration made up of multiple conical sections.
This page will be completed over time. If you are interested in making your own RC hovercraft, check out our DIY guides (our Formula 3 for example).
