Shiphandling simulator is a device that can partly imitate the true environment at sea

and is specially designed to satisfy marine education and trains and maritime research etc.One of its key techniques is to create the virtual environment at sea

and the terrain is its important component.According to the needs of the real time visual display of the shiphandling simulator

this paper analyses the requirements of the geometry precision of the important islands and background hills which are within the ships' visible scope

and brings forward the modeling methods of the hill's pileup and the hill's silhouette edges based on contour lines.It also presents the definition of error that the hill's silhouette edges graph has been given and the effective scope of application

and firstly established the error criterion of terrain model that is built in shiphandling simulator.With these two kinds of method

the size of data storage can be minimized greatly

and the requirements of high update rate and geometry precision for the real time visual display of the shiphandling simulator can be satisfied.