Abstract: Collapsible depth controller for mounting in relation to seismic cables or similar devices, comprising two wings, each being rotatably connected to a main body relative to a first axis of rotation perpendicular to the longitudinal direction of the depth controller, to be folded into an adapted room in the main body of the depth controller. The depth controller comprises a first motor for rotation of an at least partially cylindrically shaped cam plate or mushroom cam relative to its axis, the axis essentially corresponding to the longitudinal axis of the depth controller, said cam plate comprising at least one path or cam which along at least part of its length has an angular extension relative to the axis of the cam plate, at least one cam follower engaging into said cam plate and comprising a first coupling device for rotatable connection to the wings, where the first coupling device is positioned at a chosen distance from the first rotational axis of the wing.

Abstract: A depth control apparatus for seismic streamers, comprising a central unit adapted for inserted mounting in the streamer substantially in axial alignment with the streamer, a housing which can rotate about the central unit and carries at least one control wing being angularly adjustable about a transverse axis adapted to be substantially horizontal in operative position, and an electric motor for adjusting the angle of the control wing about the transverse axis. The motor is located in the central unit and is adapted to have its current supply through the streamer. The control wing is so arranged on the housing that the transverse axis in operative position runs underneath the central unit. A transmission mechanism for the angular adjustment of the control wing by means of the motor, comprises a slide member which can be moved in the axial direction of the central unit and preferably surrounds the central unit.

Abstract: Apparatus for towing a surface buoy or float, in particular a reference position buoy (1), from a marine seismic streamer (4) being adapted during operation to be immersed in the sea. The towing takes place by a means of a length of cable or the like (5A,5B) being attached to a section of the streamer and to the surface buoy respectively. At an intermediate portion of the length of cable (5A,5B) there is provided a weight or deflector device (2) being adapted during towing to impose an angular deviation of the length of cable so that the direction thereof downwards (5A) and upwards (5b) from the weight or deflector device (2), forms a mutual angle (Vb) differing significantly from 180.degree.. The point of attachment (3) at the streamer is located at an active section (4) thereof.