Inflatable boat designed as underwater vehicle

The primary use of this form of vessel is for carrying maintenance workers and their equipment to undertake underwater repairs and routine maintenance of underwater structures, such as oil rigs, production platforms and bridge supporting structures. The primarily operating profile would have the vessels launched from a surface maintenance vessel, where they will quickly travel on the surface to near the designated working area, and then completely submerge to operating depth using electric motors for propulsion and manoeuvring. The outer tubes will normally be open, and can be closed with simple valves and vents. Contained within these tubes will be an inflatable inner tube that will only be inflated underwater to provide positive buoyancy for re-surfacing. An underneath compartment will contain the main fuel tank and powerful lightweight batteries. This will be capable of being flooded to assist submerging and to maintain stability underwater. The crew will all be wearing scuba and breathing equipment, and will also be carrying the necessary tools and equipment necessary for the task in hand. All crew will be trained as helmsmen, and will be able to carry out any function in the use of the vessels at all stages of its operational profile. Means of exit and egress: The vessel is designed to allow the occupants to easily enter and exit through the open canopy roof and is constructed entirely from marine grade aluminium, with standard transverse and longitudinal framing.