The craft can only work in certain conditions
The decision to use the hovercraft follows two weeks of successful trials over water and mudflats at Morecambe Bay in Lancashire.
The 25-foot craft, called the Griffon 450TD, has also been tested at Hunstanton, Norfolk; Flint, Flintshire; West Kirby, Merseyside and Southend, Essex.
Senior helm of Morecambe lifeboat Harry Roberts said the new boat would be used in a variety of roles.
He said: "It will work in conjunction with the existing lifeboat.
"When the lifeboat is in, the hovercraft can go out, and vice versa.
"It can run for three hours at top speed before needing to refuel."
The test locations were selected because of the extensive sand or mud flats, which inhibit the response of traditional lifeboats in an emergency.
Mud rescues in particular can be very dangerous and slow to execute.
A hovercraft, however, can reach the casualty very quickly.
The hovercraft can only work at a wind speed of less than 25 knots and wave height of less than two feet.