Various numerical models that have been developed for marine environments and applied to coastal waters in USA were introduced briefly. Inter alia, with regard to an integrated monitoring and modeling system, the main features and outline of system, the system architecture for data management and representation system, and the incorporation of internet based technology were described. An example of application of an integrated system to coastal waters was also presented. The prospective research works to improve the capabilities and to advance the functionality of an integrated monitoring, modeling and management system were suggested to be the instrumentations for various monitoring parameters, the new development and/or advancement of various numerical models, the relevant internet based technologies. etc..