Abstract: A tether system for an underwater vehicle, including: a drum including a substantially cylindrical spooling segment, the spooling segment including: an axially aligned first portion with an outer circumference including a first opening; and a second portion at an axial end of the first portion and including a second opening. The system also includes a tether cable connected to the storage drum. The first and second openings form a portion of a passage from an exterior of the drum through the first portion to the outer circumference of the first portion. A tether cable for an underwater vehicle, including: a core including conductive wire or optical fiber and a buoyant jacket surrounding the core of conductive material. The buoyant jacket includes a plurality of first portions with a first outside diameter and a plurality of second portions having respective second outside diameters less than the first outside diameter.