You can make the 3D model along with the other required elements, but the integration into the simulator must be done by the developers at VSTEP:
http://www.slideshare.net/PjotrAtVSTEP/the-content-creation-workflow-of-the-ship-simulator-game (http://www.slideshare.net/PjotrAtVSTEP/the-content-creation-workflow-of-the-ship-simulator-game)