Abstract: A submersible vehicle having an outer hull which defines a hull axis and appears substantially annular when viewed along the hull axis, the interior of the annulus defining a duct which is open at both ends so that when the vehicle is submerged in a liquid, the liquid floods the duct. At least part of the outer hull is swept with respect to the hull axis A buoyancy control system may be provided. Various methods of deploying and using the vehicle are described.

Abstract: An airborne vehicle having a wing-body which defines a wing-body axis and appears substantially annular when viewed along the wing-body axis, the interior of the annulus defining a duct which is open at both ends. A propulsion system is provided comprising one or more pairs of propulsion devices, each pair comprising a first propulsion device mounted to the wing-body and positioned on a first side of a plane including the wing-body axis, and a second propulsion device mounted to the wing-body and positioned on a second side of the plane including the wing-body axis.

Abstract: An airborne vehicle having a wing-body which defines a wing-body axis and appears substantially annular when viewed along the wing-body axis, the interior of the annulus defining a duct which is open at both ends. A propulsion system is provided comprising one or more pairs of propulsion devices, each pair comprising a first propulsion device mounted to the wing-body and positioned on a first side of a plane including the wing-body axis, and a second propulsion device mounted to the wing-body and positioned on a second side of the plane including the wing-body axis.

Abstract: An airborne vehicle having a wing-body which defines a wing-body axis and appears substantially annular when viewed along the wing-body axis, the interior of the annulus defining a duct which is open at both ends. A propulsion system is provided comprising one or more pairs of propulsion devices, each pair comprising a first propulsion device mounted to the wing-body and positioned on a first side of a plane including the wing-body axis, and a second propulsion device mounted to the wing-body and positioned on a second side of the plane including the wing-body axis. A direction of thrust of the first propulsion device can be adjusted independently of the direction of thrust of the second propulsion device and/or a magnitude of thrust of the first propulsion device can be adjusted independently of the magnitude of thrust of the second propulsion device.

Abstract: A submersible vehicle having an outer hull which defines a hull axis and appears substantially annular when viewed along the hull axis, the interior of the annulus defining a duct which is open at both ends so that when the vehicle is submerged in a liquid, the liquid floods the duct. The vehicle further comprising means for rolling the vehicle about the hull axis. A buoyancy control system may be provided, and the outer hull may be swept with respect to the hull axis. Various methods of deploying and using the vehicle are described.