There are different types of hull shapes for inflatable rubber boats, such as keel, plane and catamaran. Each type has its advantages and disadvantages, so it is important to choose the one that best suits your needs.
Keel: Keelboats have an inflatable keel underwater that provides some stabilization to the boat. Often a slightly lower price. This can be useful for fishing or for keeping the boat on course. Disadvantages of keelboats are that they can be more difficult to maneuver in tight spaces, they tend to wander from side to side when towing, they are not as stable, they can be a bit slower than other types of boats.
Planes: have a flat underside and no keel, making them light and fast. They are easy to maneuver and can be great for exploring small waters in calmer waters. Disadvantages are that they can be unstable and can roll more easily than keelboats, can damage the bottom when driving up rocks, etc.
Catamaran: Catamaran hulls have two parallel hulls that give the boat high stability and make it easy to maneuver. Easier to get close to land and works well in the sea. They can be useful for fishing, diving and keeping the boat on course. The downside is that they may have a slightly higher price than other types of boats.
It is difficult to say which type of hull is the best because it depends on what you plan to use the boat for. It may be a good idea to try different types of inflatable boats and see what suits you best.