Over the past ten years, there has been explosive growth in the size of ships in general and containerships in particular. The ship-to-channel ratios now provide less margins of safety, and present significant challenges to port designers, pilots, tug companies, and marine operations. Full-mission ship simulation, also known as FMSS, is gaining acceptance as a cost-effective way to evaluate whether transits are safe and under what conditions. Additionally, simulations can be of great assistance in the preliminary design process to reduce dredging costs and increase port efficiencies.