What is a RIB and who is this type of boat suitable for? The term RIB is an abbreviation for "Rigid Inflatable Boats" and this type of boat is a combination of fiberglass hull and a pontoon. RIBs on the market today are often from sizes around 12-13 feet and all the way up to 28-30 feet. There are also some differences between the types of RIB that you should be aware of, especially when it comes to equipment and comfort level on board.