Abstract: Tendon systems described herein may include a cellular tendon main body system having at least two essentially parallel pipe strings and may be used to moor a floating structure to a seabed. Hybrid tendon systems may include one or more tendon modules, where at least one tendon module includes a cellular tendon main body system. Where more than one module is used, the modules may be different types or designs of tendon systems, such as conventional single-string tendon or cellular tendon, according to the performance requirements of the module. Cellular tendon main body systems described herein enable the overall tendon, and subsequently the floating structure, to be used in ultra-deep waters and/or with heavy topsides.