Techniques are disclosed relating to marine geophysical surveys. Various output characteristics of a vibratory source may be modified based on whether a source is targeting an identified portion of a survey area. The portion of the survey area may be detected during the survey or may be pre-identified. In some embodiments, a survey system drives a vibratory source using digital codes having different lengths based on whether the source is targeting an identified portion of a survey area. The disclosed techniques may improve imaging of geology under certain types of formations or may reduce environmental impact, in various embodiments.

Disclosed is a system 1000 for determining a virtual representation of at least part of an environment 800 that is navigable by a ship 700. The system has at least one beacon 101, 102, 201, 202, 301, 302, 401-403 remote from the ship. The or each beacon comprises at least one sensor 411-415 for sensing surroundings information representative of at least part of the environment, a transmitter 420, and a controller 430 connected to the at least one sensor and configured to cause the surroundings information to be transmitted via the transmitter. The system also comprises a control centre 500 remote from the ship. The control centre comprises a receiver 520 configured to receive the surroundings information, and a control unit 530 connected to the receiver and configured to determine a virtual representation of at least part of the environment based on the surroundings information. The virtual representation may comprise a topographical map, such as a LIDAR map.

Disclosed is a system 1000 for determining a virtual representation of at least part of an environment 800 that is navigable by a ship 700. The system has at least one beacon 101, 102, 201, 202, 301, 302, 401-403 remote from the ship. The or each beacon comprises at least one sensor 411-415 for sensing surroundings information representative of at least part of the environment, a transmitter 420, and a controller 430 connected to the at least one sensor and configured to cause the surroundings information to be transmitted via the transmitter. The system also comprises a control centre 500 remote from the ship. The control centre comprises a receiver 520 configured to receive the surroundings information, and a control unit 530 connected to the receiver and configured to determine a virtual representation of at least part of the environment based on the surroundings information. The virtual representation may comprise a topographical map, such as a LIDAR map.

The invention relates to a tug controller and a tug for maneuvering a towed vessel, comprising a dynamic positioning system, and a tow equipment comprising a towline connected to the towed vessel, wherein the tow equipment is automatically controlled by the dynamic positioning system based on a plurality of input parameters.

Techniques are disclosed relating to marine geophysical surveys. Various output characteristics of a vibratory source may be modified based on whether a source is targeting an identified portion of a survey area. The portion of the survey area may be detected during the survey or may be pre-identified. In some embodiments, a survey system drives a vibratory source using digital codes having different lengths based on whether the source is targeting an identified portion of a survey area. The disclosed techniques may improve imaging of geology under certain types of formations or may reduce environmental impact, in various embodiments.

A vessel for towing another vessel comprises a hull, a tow cable coupled to the hull, a hook having a first leg fixed to a free end of the cable, a second leg including a free end and a hook bottom. The first and second legs form an opening for receiving a rope located at the vessel and launched from another vessel. The first and second legs extend in a main plane. A rope positioning system positions a rope and a hook support for the hook with respect to each other such that the rope extends in transverse direction of the main plane at the opening of the hook when the hook is linked to the hook support. A rope pressing system presses the rope the hook towards the hook bottom when the hook is linked to the hook support, creating a clamping force between the legs and the rope.

A vessel for towing another vessel comprises a hull, a tow cable coupled to the hull, a hook having a first leg fixed to a free end of the cable, a second leg including a free end and a hook bottom. The first and second legs form an opening for receiving a rope located at the vessel and launched from another vessel. The first and second legs extend in a main plane. A rope positioning system positions a rope and a hook support for the hook with respect to each other such that the rope extends in transverse direction of the main plane at the opening of the hook when the hook is linked to the hook support. A rope pressing system presses the rope the hook towards the hook bottom when the hook is linked to the hook support, creating a clamping force between the legs and the rope.

An all around towing system (33) for a tug (31) comprising a heavy plate (40) mounted on a deck of the tug, an upper rail segment (42) and a lower rail segment (44) disposed on the upper and lower surfaces of an outer edge of the heavy plate, respectively, a carriage (46) movable along the upper and lower rail segments, a set of bearing wheels (47, 48) arranged for guiding the carriage along the upper and lower rail segments, characterized in that the heavy plate further comprises respective upper and lower grooves (43, 45) on the upper and lower surfaces of the heavy plate, and in that the upper and lower rail segments are respectively mounted in the upper and lower grooves of the heavy plate.

An all around towing system (33) for a tug (31) comprising a heavy plate (40) mounted on a deck of the tug, an upper rail segment (42) and a lower rail segment (44) disposed on the upper and lower surfaces of an outer edge of the heavy plate, respectively, a carriage (46) movable along the upper and lower rail segments, a set of bearing wheels (47, 48) arranged for guiding the carriage along the upper and lower rail segments, characterized in that the heavy plate further comprises respective upper and lower grooves (43, 45) on the upper and lower surfaces of the heavy plate, and in that the upper and lower rail segments are respectively mounted in the upper and lower grooves of the heavy plate.

A method for operating a towing winch and an electric drive for a towing winch, the towing winch including a rotatable winch drum for spooling a spoolable medium, and an electric motor operably coupled to the winch drum to rotate the winch drum, wherein the electric drive is configured to be operably coupled to the electric motor, and configured to control, during a towing of at least one object connected to the spoolable medium, a tension of the spoolable medium between the winch drum and the at least one object to be towed to be equal to or lower than a tension limit value; and monitor, during the towing, a roll angle of the tug, and in response to the monitored roll angle of the tug being outside of a predetermined range, lower the tension limit value providing roll compensation.