This family specification covers optical telecommunication cables to be used as underwater cables. Types of cables included in this family specification are "underwater cables" for lakes, river crossings etc. and are for cable systems without power feeding requirements. This specification does not cover repair capability. Requirements of the sectional specification for optical telecommunication cables EN 187100 (EN 60794-3) are applicable to cables covered by this standard. Clause 5 of this standard describes a blank detail specification for optical telecommunication cables to be used as underwater cables. It incorporates some minimum requirements common to all European Countries. Detail specifications may be prepared based on this family specification following in particular requirements of clause 5.