A cable leveling device is attached to a streamer cable by providing an adapter module secured between two seismic streamer cable sections with one of the cable strain members secured to the adapter. An overlying coaxial housing is mounted for rotation about the adapter module so as to rotate with respect to the module. The overlying housing carries leveling apparatus in the form of paravanes as well as depth sensing and other apparatus, with the top part of the overlying housing containing a hollow or foam-filled buoyant portion, and with the bottom portion of the housing containing batteries, electronics and sensing devices, such that the housing is maintained in a vertical orientation because of its buoyant top portion and weighted bottom portion. The cable leveling device is secured not by collars to the resilient outer casing of a seismic streamer cable but rather to a rigid adapter module between cable sections, which in turn is secured to a single strain member, with the adapter providing a relatively short base line and thus a shorter leveling device. In one embodiment the housing is divided to provide a two-part clamshell arrangement clamped over the adapter module, with the adapter module having circumferential slots at either end thereof into which circumferential inwardly protecting ridges of the housing project such that rotation of the housing relative to the adapter module is facilitated.
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