Sea space planning and congestion management is receiving more attention. H
owever, little work on sea space capacity and strategy analyses can be foun
d in the literature. Compared to other transportation systems, a sea space
system has some special features that require consideration. The system cap
acity also depends on the pattern of traffic using the system. In this pape
r, we model a sea space as a directional network and capacity models for be
rthing areas, anchorage areas, fairways and their intersections, as well as
the entire sea space system are developed. These models can be used to com
pute capacity for any given traffic pattern which can be extracted from ves
sel trip records or from traffic forecasts. To implement these models, a so
ftware system called Sea Space Capacity and Strategy Analysis System (SCSAS
) has been developed in Visual C++ and is now being used in Singapore.