We present a virtual simulation of ships and ship-mounted cranes. The simulation is carried out in a Cave Automated Virtual Environment (CAVE). This simulation serves as a platform to study the dynamics of ships and ship-mounted cranes under dynamic sea environments and as a training platform for ship-mounted crane operators. A model of the (Auxiliary Crane Ship) T-ACS 4-6 was built, converted into an OpenGL C++ API, and then ported into the CAVE using DiverseGL (DGL). A six-degrees-of-freedom motion base was used to simulate the actual motion of the ship. The equations of motion of the ship are solved using the Large Amplitude Motion Program (LAMP), while the equations of motion of the crane payload are numerically integrated; the interaction between the payload and the ship is taken into consideration. A nonlinear delayed-position feedback-control system is applied to the crane and the resulting simulation is used to compare the controlled and uncontrolled pendulations of the cargo. Our simulator showed a great deal of realism and was used to simulate different ship-motion and cargo transfer scenarios. This work received support from the Office of Naval Research under Grant No. N00014-99-1-0562. / Master of Science