are of particular concern when a simulation is used for licensing or training related to remission of sea-time.

To address these concerns, simulators and simulations should be validated based on proposed use and required level of performance. All modifications should be documented and the simulation revalidated. The extent to which accuracy of a simulation needs to be validated should depend on its proposed use.

An approach to simulator and simulation validation might follow the commercial air carrier industry process, which relies on both objective and subjective validation. The objective validations could include development of a "realism rating" based on an assessment of factors such as image portrayal and predicted ship trajectories. The subjective validations could be conducted by an impartial panel of experts.

Many organizations and individuals have an interest in the development of these standards. There are a number of national and international organizations that could effectively work toward the consensus necessary to promulgate standards that would be acceptable to all parties.

There are number of areas where additional research in hydrodynamic and mathematical modeling could be applied to improve the accuracy of simulators and simulations. On a process level, value could be gained from the development of standard method for the exchange of models or modeling coefficients. Also, if models were developed in modules, validation of the simulations and simulation characteristics modifications would be facilitated, as would replacement of outdated modules. Finally, simulation models could be improved through greater public access to existing proprietary hydrodynamic and other towing-tank data.

Additional research is needed to extend databases in areas such as ship maneuvering coefficients and anchoring evolutions. Also, the application of computational methods for determining pertinent hydrodynamic parameters offers great promise as a solution to current problems in modeling and ship-bridge simulators. Ship modeling would be improved through development and implementation of research codes to be applied to specific computational tasks of maneuvering simulation.

Full-scale real-ship experiments would advance the state of practice in modeling, particularly for shallow and restricted waters with banks. Modeling for operations at slow speed and with reversing propeller situations also needs improvement.

Drown, D.F., and R.M. Mercer. 1995. Applying marine simulation to improve mariner professional development. Pp. 597–608 in Proceedings of Ports '95, March 13–25, 1995. New York: American Society of Civil Engineers.