DESCRIZIONE
Apparatus (14) for supporting a cable (16) in a fluid-filled pipe (10) extending through an underground borehole, comprising a body (14) for connection to an end of the cable extending along the pipe, the body being buoyant in the fluid filling the pipe, such that when the body is connected to the end of the pipe, it floats at or near the surface (15) of the fluid in the pipe. A method of supporting a cable in a fluid-filled pipe using such apparatus, comprises connecting the cable to the body, and dropping the body into the pipe so as to float on the surface of the fluid filing the pipe.