We present a simple process for the fabrication of very long SiC-based coaxial nanocables (NCs). The versatility of this technique is confirmed by the ability to change the chemical composition of the NC outer layers from silica to carbon and boron nitride. The NCs consist of a SiC core approximately 30 nm in diameter with lengths up to several hundred of nanometers. The thickness of the coating is in the range 2-10 nm. The morphology and structural characterization of the NCs is investigated by scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM), respectively, and their chemical composition is probed by electron energy loss spectroscopy (EELS). A vapor-solid growth mechanism is proposed to explain the growth of SiC-based NCs of various chemical compositions, depending on the chemical nature of the vapor phase. Because of the large quantity of very long and interlaced NCs produced during the synthesis, the macroscopic aspect of the as-grown material is like a self-supported felt.