A rigid inflatable boat capable of submerging and operating underwater has been developed by Severn (7) Shipbuilders in Gloucestershire, UK.

The boat is intended for carrying workers and equipment to underwater structures in need of repair or maintenance work, such as oil rigs and bridge structures. Since it is capable of travelling on water as well as submerged, the vessel can quickly travel to the right location on the surface before submerging down to the desired depth.

The vessel consists of outer and inner tubes, plus an underneath compartment that holds the main fuel tank and lightweight batteries. The underneath compartment can be flooded to aid submerging and keep the vessel stable underwater. The outer tubes will normally be open, but can be closed if necessary. The inner tubes are inflatable and will be used to provide positive buoyancy when its time to resurface.