A buoyant element for conferring buoyancy on a subsea structure or apparatus has a floodable envelope that contains a mass of buoyant spheres and a void extending between the spheres. Openings penetrate the envelope, in fluid communication with the void. One or more one destruction devices are arranged to destroy at least one of the spheres within the envelope in use. After the envelope has been submerged and flooded to fill the void between the spheres with water, the destruction devices are imploded to create shockwaves that expand the void by sympathetic implosion of the spheres. Additional water is admitted into the envelope through the openings to fill the expanding void, thereby ballasting the buoyant element.

A method comprising: providing an autonomous vehicle (AV) with a first estimated position of a target; directing the AV to travel toward the first estimated position at a constant velocity; receiving echo signals of transmitted sonar signals, the echo signals indicating a range and an azimuth of the target; determining a depth difference of the AV and the target based on the received echo signals, the depth difference being determined based on changes to the range and azimuth of the target over time; and in response to a depth difference existing, re-directing the AV toward a second estimated position of the target generated from the depth difference.

A method comprising: providing an autonomous vehicle (AV) with a first estimated position of a target; directing the AV to travel toward the first estimated position at a constant velocity; receiving echo signals of transmitted sonar signals, the echo signals indicating a range and an azimuth of the target; determining a depth difference of the AV and the target based on the received echo signals, the depth difference being determined based on changes to the range and azimuth of the target over time; and in response to a depth difference existing, re-directing the AV toward a second estimated position of the target generated from the depth difference.

A mine countermeasure device for disabling an undersea mine, and underwater transport, and methods therefor. The mine countermeasure device operates to mask, cancel or neutralise (detonate) the undersea mine. The mine countermeasure device is deployed, together with a plurality of other mine countermeasure devices from an underwater transport, for example autonomously. The underwater transport preferably carries out a scan of an area known to be mined, in order to identify undersea mines. The underwater transport is capable of autonomous operation over the horizon to deliver plurality of mine countermeasure devices. The mine countermeasure device targets particular sensors on the undersea mines.

A mine countermeasure device for disabling an undersea mine, and underwater transport, and methods therefor. The mine countermeasure device operates to mask, cancel or neutralise (detonate) the undersea mine. The mine countermeasure device is deployed, together with a plurality of other mine countermeasure devices from an underwater transport, for example autonomously. The underwater transport preferably carries out a scan of an area known to be mined, in order to identify undersea mines. The underwater transport is capable of autonomous operation over the horizon to deliver plurality of mine countermeasure devices. The mine countermeasure device targets particular sensors on the undersea mines.

A system for detecting and locating submerged underwater objects having neutral buoyancy comprising mechanically steered sonar to image the water column comprises mechanically steered sonar with a single emission channel, to perform the insonification of a first individual sector in a first pointing direction by a single first acoustic pulse, the sonar forming a single reception channel suitable for acquiring a first acoustic signal resulting from insonification, the mechanically steered sonar being mounted on a carrier to advance in a main direction, the first pointing direction substantially lateral to the carrier and the first individual sector exhibits a wide relative bearing aperture and a narrow elevation aperture, the mechanically steered sonar comprising a mechanical pointing device to tilt the first pointing direction about an axis of rotation substantially parallel to the main direction allowing the sonar to acquire first acoustic signals resulting from insonifications performed in different pointing directions.

A system for detecting and locating submerged underwater objects having neutral buoyancy comprising mechanically steered sonar to image the water column comprises mechanically steered sonar with a single emission channel, to perform the insonification of a first individual sector in a first pointing direction by a single first acoustic pulse, the sonar forming a single reception channel suitable for acquiring a first acoustic signal resulting from insonification, the mechanically steered sonar being mounted on a carrier to advance in a main direction, the first pointing direction substantially lateral to the carrier and the first individual sector exhibits a wide relative bearing aperture and a narrow elevation aperture, the mechanically steered sonar comprising a mechanical pointing device to tilt the first pointing direction about an axis of rotation substantially parallel to the main direction allowing the sonar to acquire first acoustic signals resulting from insonifications performed in different pointing directions.

A vehicle seat backrest having a body, a cover layer designed to be placed at the back of the body and covering at least a portion of the body, a storage apparatus defining a storage volume over a portion of the cover layer, and a fixation device for attaching the storage apparatus onto the cover layer. The fixation device includes at least one fixation support and at least one pin. The cover layer is overmolded onto the at least one fixation support. The at least one pin mates with the at least one fixation support and the storage apparatus so as to attach the storage apparatus to the cover layer.

An embodiment of an apparatus includes a transducer array and a controller that is operable to cause the transducer array to generate a signal having a frequency, and to direct the signal toward an object having a resonant frequency that is approximately equal to the frequency of the signal. For example, an embodiment of a mine-hunting-and-neutralizing apparatus may generate an acoustic wave with a transducer array, and may disable or destroy a mine by directing the wave toward the mine. The apparatus generates the acoustic wave having a frequency that is approximately equal to the natural frequency of a component of the mine such that the wave causes the component to resonate in a manner that is sufficient to disable the mine from detonating, or that is sufficient to cause the mine to detonate. For example, if the component is the detonator, then the wave causes the detonator to resonate at an energy level that is sufficient to render the detonator unable to detonate the mine, or that is sufficient to cause the detonator to detonate the mine.

An embodiment of an apparatus includes a transducer array and a controller that is operable to cause the transducer array to generate a signal having a frequency, and to direct the signal toward an object having a resonant frequency that is approximately equal to the frequency of the signal. For example, an embodiment of a mine-hunting-and-neutralizing apparatus may generate an acoustic wave with a transducer array, and may disable or destroy a mine by directing the wave toward the mine. The apparatus generates the acoustic wave having a frequency that is approximately equal to the natural frequency of a component of the mine such that the wave causes the component to resonate in a manner that is sufficient to disable the mine from detonating, or that is sufficient to cause the mine to detonate. For example, if the component is the detonator, then the wave causes the detonator to resonate at an energy level that is sufficient to render the detonator unable to detonate the mine, or that is sufficient to cause the detonator to detonate the mine.