A buoyancy adjusting device for an underwater device is described the device comprising: a tube having first and second ends; a resilient mechanism located at the first end of the tube and extending towards the second end of the tube; an opening near the second end of the tube; a catch at the second end of the tube; 5 and at least one block insertable into from the first end of the tube to adjust the buoyancy.

A seabed object detection system is provided. The system can include a receiver array. The receiver array can include a plurality of receivers disposed on a plurality of streamers. The plurality of streamers can include a central port side streamer, a central starboard side streamer, an auxiliary port side streamer and an auxiliary starboard side streamer. The system can include a source array. The source array can include a plurality of sources. The plurality of sources can include a central port side source, a central starboard side source, an auxiliary port side source, and an auxiliary port side streamer. The source array towed during a first pass can define a first path. The source array towed during a second pass can define a second path. The first path can be interleaved with the second path such that the first path overlaps the second path.

An image recording method in an image processing apparatus, includes the steps of acquiring, from a plurality of cameras, respective video images which the plurality of cameras start capturing in the sea before a first light that is lit in a first color is turned on and end capturing after a second light that is lit in a second color is turned on after the first tight is turned on, detecting, for each of the video images, a difference in luminance between chronologically adjacent frames in the video image, associating times of frames between the video images on the basis of the difference, and recording the video images with the associated times in a recording medium.

In an underwater glider, stability and versatility can be enhanced by the use of a high wing design. In a high wing design, a centerline of the wings extending from the sides of the body of the glider are located above a relative centerline of the body of the glider. The relative centerline of the wings may rise continuously from a region where the wings attach to the body to respective ends of the wings. In particular for a blended wing glider, a top surface of the glider is level in a line extending between ends of each wing.

An underwater data capture and transmission system has a base configured to sink in water, at least one sensor configured to capture data while submerged in water, a processing unit configured to receive data collected by the sensor, and a variable buoy. The variable buoy has a ballast system configured to adjust a depth of the variable buoy in the water, and a communication device configured to transmit data to a remote communications device. The system further has at least one tether connecting at least the base, the processing unit, and the variable buoy.

A hierarchical data acquisition system and method applied to a marine information network are provided. Multiple sensor nodes are arranged in clusters, each of the clusters includes a cluster head node and multiple ordinary nodes. The multiple ordinary nodes acquire data information of a seafloor and transmit the acquired data information to the cluster head node, and the cluster head node aggregate the data and transmits the aggregated data to an autonomous underwater vehicle, reducing energy consumption of each of the sensor nodes, prolonging service lives of sensors of a data acquisition layer, and improving data acquisition efficiency of a data acquisition layer. In addition, after each of data acquisition periods, a sensor node in each of the clusters is selected as a cluster head node in a next data acquisition cycle. Cluster head nodes are continuously updated in cycles.

Seismic autonomous underwater vehicles (AUVs) for recording seismic signals on the seabed. The AUV may be negatively buoyant and comprise an external body (which may be formed of multiple housings) that substantially encloses a plurality of pressure housings. Portions of the external body housing may be acoustically transparent and house one or more acoustic devices for the AUV. The AUV may comprise a main pressure housing that holds substantially all of the electronic components of the AUV, while a second and third pressure housing may be located on either side of the main pressure housing for other electronic components (such as batteries). A plurality of external devices (such as acoustic devices or thrusters) may be coupled to the main pressure housing by external electrical conduit. The AUV may comprise fixed or retractable wings for increased gliding capabilities during subsea travel.

An underwater vehicle system includes: a first underwater vehicle configured to perform work in water while moving in a predetermined proceeding direction; and a second underwater vehicle configured to replace the first underwater vehicle and perform work in water. When the second underwater vehicle replaces the first underwater vehicle, the second underwater vehicle approaches the first underwater vehicle based on a signal transmitted from the first underwater vehicle.

The invention relates to a method for determining a water current velocity profile in a water column by registration of a deviation between a first position and a second position of an underwater vehicle travelling in the water column. A batch of underwater vehicles is deployed from a surface vessel into the water. The vehicle(s) steers to the first position, which for the first batch is a predefined estimated position (PEP). The vehicle is by first means recording the second position, which is the actual position (AP). The difference ΔP between the predefined estimated position PEP and the actual position is registered and based on the difference a deviation data set is calculated. An updated current profile or stack of horizontal water current velocities UV is determined.

The present invention discloses an air-sea buoy monitoring system towards mid-latitude ocean including a meteorological data acquisition system, an underwater data acquisition system and a central processor. It collects data through different sensors via both meteorology and underwater data acquisition systems, and then transmits data to a central processor. The data collected by meteorology and underwater data acquisition systems will be analyzed and visualized via an information processing system and an image processing system. An alarm module is provided to alarm when meteorological data/value exceeds a certain threshold. This buoy monitoring system ensures the long term, continuous and simultaneous observation of multi-level/multi-factors for the air-sea interface and underwater oceanic environment at a fixed point, with the data being transmitted to shore-based data center in real time via communication satellites.