A RHIB (or RIB) is a light but high performance and large capacity boat built with a solid, shell-shaped and flexible tubing around. 

The design is stable and seaworthy. The inflatable collar allows the ship to maintain buoyancy if a large amount of water is shipped on board due to bad sea conditions.

The RHIB is a development of the inflatable boat.

Uses include work boats (shore support services or larger ships) in trades that operate on water, military ships, where they are used in patrol roles and for the transport of troops between ships or on land, and lifeboats.

WHY IS IT CALLED RIB?

The proper way to call it is RHIB and stands for RIGID-HULLED INFLATABLE BOAT. It differs from the standard inflatable boat because of a hull typically made in fiberglass instead of a soft bottom enforced with pranks.

RIB is typically done on bbq during spring season, but became the most popular in common speech.

FRIB

The F ahead stands for FOLDABLE and represents all those ribs which are studied to be stored in small places before being used.

FIB

This is the most interesting.. FLYING INFLATABLE BOAT.

A flying rib, in Malta a well known pioneer HENRY ROTA made his own in the ’90.

Here’s the video: