What underwater boat is fully autonomous and made by BAE Systems?
Submarine A submarine (or simply sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term most commonly refers to a large, crewed vessel. It is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. The noun "submarine" evolved as a shortened form of "submarine boat"; by naval tradition, submarines are usually referred to as "boats" rather than as "ships", regardless of their size ("boat" is usually reserved for seagoing vessels of relatively small size).
Rigid buoyant boat The rigid buoyant boat (RBB) is a light-weight but high performance and high capacity boat. Based on the concept of a Rigid-hulled inflatable boat (RHIB), it has a tube/sponson manufactured from a solid material such as moulded polyethylene or aluminium and therefore being much more robust than the fabrics commonly used. Boats with foam filled collars such as the "secure all-around flotation equipped" (SAFE) boats employed by the US Coast Guard can also be classified as Rigid Buoyant Boats rather than "true" RHIBs as the collar is solid foam rather than inflated. The handling tends to be very similar to a RHIB; likewise they will remain afloat (buoyant) even if completely flooded. Aluminium RBBs tend to be bespoke (custom-made to specification) or low-volume products whilst the tooling cost of rotomolded polyethylene boats tends to require these to be higher volume products. At least three manufacturers are producing rotomolded boats of this type. One supplier has demonstrated the robustness of the boats by dropping one from a crane onto a concrete car park. The U.S. Navy’s small unit riverine craft and the Coast Guard’s Defender class 25 ft boats are examples of RBBs. Some boat builders make RBB's as workboat from HDPE sheets welded together. Similar deep V-hull can be made for good seakeeping. If buoyancy chambers are filled the hull becomes truly unsinkable and extremely indestructible making the RBB very suitable for rough conditions. The RBB serie of Tideman Boats is a good example.