The Marine Modeling and Analysis Branch (MMAB) of EMC has been involved in coupled modeling for many years. Notably, we are working on coupled Atmosphere-Ocean-Wave modeling for hurricanes, and coupled wave-surge modeling for inundation and coastal hazards. The presentation will focus on lessons learned from these projects. The architecture of coupling and coupler will be discussed, as well as relevant examples of issues and solutions for the MMAB applications. Most importantly, from our experience it is realized that present coupling strategies are not conducive to direct improvement of operational systems, and hence not likely to be introduced in operations. Alternate coupling strategies, based on advancing physical model improvements, are suggested.