‘Ground Effect Vehicle’ (GEV) and ‘Wing-in-ground’ (WIG) are aircraft-like vessels that utilise a phenomenon known as ‘ground effect’ to float above the water’s surface on a cushion of air generated by the lifting surfaces.
These crafts often consist of two large wings, often with the addition of a tailplane, which enables them to take advantage of aerodynamic forces like an aircraft but also land on the water like a boat. The size of these crafts can range from giant Ekranoplan’s such as the Soviet Caspian Sea Monster designed to cross inland seas, small ferries, to small experimental personal watercraft.
Ground Effect Boats differ from aircraft in that they are not designed to leave ‘ground effect’ and climb away like a regular plane. This is often dictated by a lack of continuous engine power however vessels may be able to climb out of ground effect temporarily to pass obstacles such as terrain. The exact altitude these vessels can cruise in ‘ground effect’ is heavily dependent on the wingspan and aerodynamics of the craft, typically this will be between 25-50% of the craft’s wingspan.
The main advantage of flying in Ground Effect is the reduction of drag which can double the efficiency compared to flying at higher altitudes and allow for speeds over 6x faster than a traditional displacement watercraft. Large seabirds such as Albatross use this exact same principle to cross large oceans.
Despite being able to fly, the International Maritime Organization and most countries still classify GEV’s as marine vessels and categorise them as either Class-A, Class-B, Class-C according to how high they can climb above the surface in the case of emergency and for overcoming obstacles
Have you seen a Ground Effect Boat (GEB) or Wing In Ground (WIG) craft before? Let us know in the comments below