Hollow Braided Rope
Hollow braid rope is an easily spliced cord of a diamond braid construction; most common in nylon or polypropylene. Constructed of 8, 12 or 16 strands, hollow braided rope is the same as the diamond braided rope on the surface, but is coreless. Because it does not have a core, it makes it easy to splice. Hollow braided rope is braided into a circular pattern with half of the strands going clockwise and the other half going counter clockwise. The strands can interlock with either twill or plain weave.
E-Rigging.com has a large selection of polypropylene hollow braided rope.