This Recommendation deals with the characteristics of the optical fibre submarine cables used in [ITU T G.973], [ITU-T G.973.1], [ITU-T G.974] and [ITU-T G.977]. It covers transmission characteristics of optical fibre submarine cables, optical fibres used in submarine cables, including mechanical characteristics and resistance to the environment and other electrical characteristics. It also covers the transmission characteristics of the single- and hybrid-fibre type elementary cable sections. Any specific information regarding the characteristics of optical fibre submarine cables are included in the relevant optical submarine system's Recommendations.