Marine algae biomass energy source is increasing getting approval from policy maker and community. Beside production of seaweed for biomass energy, seaweed plantation has benefit for food, cosmetic, gelatin and pharmaceutical products. Large production of biomass will require deployment of very large multibody floating structure offshore. To ensure that the system is reliable, design needs to be built, a mooring component for the mooring system, need to be properly sized to provide reliable strength for position keeping. This paper present, result of hydrodynamic test carried in UTM lab to determine coefficient required for the design and simulation of mooring system for very large floating structure for offshore aquaculture structure for ocean plantation, the paper also present safety and efficiency of the mooring system. Hydrodynamic test is traditionally used to secure coefficient require for design for environment for ship structure and offshore platform hydrodynamic interaction. The case of seaweed biomass is unique because the seaweed interacts directly and moves with the environment. The obtained the coefficient is used to model the static moorings system that assess the tension, tilt, safe mass and motion of the mooring components. Interpolated time dependent currents from the towing tank are used to estimate dynamic response of the mooring as well as the draft of the mooring components, the overall analysis is use to select required mooring components of the system. The outcome of the test presented in this paper will help for future development of offshore aquaculture system and multibody system deployment and analysis