Abstract: A water-tight optical fiber communications cable constructed without the use of a viscous water-blocking compound other than in the buffer tubes thereof. One or more water swellable yarns are helically wrapped around the central strength member to absorb any water which may be present in the interstices between the central strength member and the buffer tubes. Additionally, a water swellable tape is disposed between the core and the jacket of the cable to absorb water from the interstices between the buffer tubes and elements overlaying the core of the cable.