Tropical cyclone research from the operational, applied viewpoint falls into two categories—forecasting research and decision-making research. One aspect of the latter is the typhoon haven evaluations being done by the Naval Environmental Prediction Research Facility in the western Pacific and Indian Ocean regions. Some 23 ports and harbors are being evaluated as to their suitability as tropical cyclone havens. The aim is to aid decision makers and commanding officers of ships in evaluating a typhoon threat situation and to assist them in making better decisions in regard to evasion, remaining in port, or the seeking of shelter within a harbor or specific section of a harbor. A number of aspects of the haven studies are discussed.