Fragmented guidance and unbalanced climate adaptation efforts for tangible and intangible cultural heritage are challenging the long-term sustainability of coastal tourism destinations. Conceptualizing and quantifying adaptation paradigms that optimize cultural heritage preservation from multi-faceted perspectives under fiscal constraints is highly prioritized by coastal tourism destinations. Informed by the Modern Portfolio Theory, this study developed, tested, and evaluated four adaptation paradigms using machine-learning approaches to optimize the historical significance, tangible, and intangible values of multi-type cultural heritage in Gulf Island National Seashore across a 30-year planning horizon under varying fiscal constraints. Results indicated that adaptation paradigms can provide transformative and flexible preservation portfolios to preserve tangible and intangible uses when facing degradation or loss from inadequate funding and intensifying climate threats. The mixed-paradigm framework optimizes preservation efforts between tangible and intangible cultural heritage quantitatively and can be generalized to coastal tourism destinations globally as a sustainable climate adaptation decision support tool.