Hydrofoils are specialized boat designs that use underwater foils to generate lift.

Hydrofoils are basically wings, just like an airplane wing. A foil can generate enough lift to raise a boat hull above the water’s surface. 

Foils are beneficial because they raise boat hulls above the water, which reduces the drag caused by water resistance. This allows a boat to achieve higher speeds with less power.

This lift also increases vessel stability and reduces motions, including pitching and rolling, making a boat ride smoother and more comfortable.

A hydrofoil system typically uses one or more wing-like structures called foils. They are securely mounted on struts, or supports, under the boat hull. 

Hydrofoils are used in a variety of applications, including:

  • Commercial passenger ferries
  • Military vessels
  • High-speed racing sailboats
  • Pleasure boats. 

Hydrofoils are particularly well-suited for operating where wave action is a concern.

One of the earliest and most successful applications of hydrofoils was in the development of hydrofoil passenger ferry boats.

These specialized vessels lifted out of the water and could achieve higher speeds with less power. 

They were, and are, particularly popular in regions with crowded waterways and in places where ferry speed is critical, like in the waters around major cities and between islands.

Hydrofoils have also been used extensively in military vessels, including fast attack craft and patrol boats. 

Military vessels use hydrofoils to achieve high speeds which would not be achievable without a hydrofoil.

In recent years, hydrofoil technology has been applied to high-speed pleasure boats, and even sailboats. 

Hydrofoils now enable recreational boaters to achieve speeds of up to 50 knots or more. 

High-speed hydrofoiling boats are typically designed for thrill-seeking and racing, and are often used in regattas and competitions, or purely for recreational purposes.

Overall, hydrofoils offer dramatic advantages in terms of speed, stability, and maneuverability.