This research develops a generalizable cost model for a floating offshore wind farm consisting of wind turbines mounted on semi-submersible platforms deployed along coastal and island developing nations. A case study is developed for the semi- submersible-based wind farm model as deployed off the coast of St. Thomas, in the U.S. Virgin Islands. The case study analyzes wind resources, bathymetric data, and environmental concerns to forecast the levelized cost of energy of such a project. The analytical model developed for this work is based on a detailed literature review of cost models that have been developed for floating offshore wind systems, and recent empirical cost data from public sources. This model adapts and synthesizes several methodologies to assess floating offshore wind farm costs, including the use of ORBIT, a National Renewable Laboratory Model balance-of-system model. This work suggests several coastal and island developing nations which have significant offshore wind resources as potential sites to be analyzed with the model. It also found atmospheric and oceanic data for these regions in order to estimate the range of levelized cost of energy for such systems.