Unlike basic jacketed wires, properly engineered waterproof cables rely on internal water-blocking gels, tapes, and specialized polymers to stop moisture tracking in its tracks. The basic mechanical failure mechanism for optical fibres is the slow to rapid growth of any glass imperfections in the fibre caused by the fibre being under stress. Craig. In this article, we give a complete overview to choosing optical cables suited for various environmental factors. Depending on their design and intended application, cables are classified as water-resistant, waterproof, or watertight.