Abstract: A method of obtaining data with a sensor of an autonomous underwater vehicle (AUV), the AUV comprising a bladder which contains a gas and is exposed to ambient water pressure. A downward thrust force is generated which causes the AUV to descend through a body of water, wherein the bladder contracts as the AUV descends due to an associated increase in the ambient water pressure, the contraction of the bladder causing the gas to compress and the AUV to become negatively buoyant. Next the AUV lands on a bed of the body of water. After the AUV has landed on the bed, the sensor is operated to obtain data with the AUV stationary and negatively buoyant and a weight of the AUV supported by the bed.

Abstract: A submersible device (2) for deploying or retrieving autonomous underwater vehicles (AUVs), the submersible device comprising: two or more platforms (130) arranged in a stack (3a, 3b), wherein each platform is configured to carry two or more of the AUVs; a port (300, 310); and a transfer mechanism (200) comprising a transfer device (210) arranged to load or unload the AUVs onto or from the platforms, and an actuator arranged to move the transfer device between the platforms and the port in order to transfer the AUVs between the platforms and the port.