The paper is dedicated to real time simulation of sport boats, particularly a kayak and high-speed skimming boat, for training goals. This training is issue of the day, since kayaking and riding a high-speed skimming boat are both extreme sports. Participating in such types of competitions puts sportsmen into danger, particularly due to rapids, waterfalls, different water streams, and other obstacles. In order to make the simulation realistic, it is necessary to calculate data for at least 30 frames per second. These calculations may take not more than 5% CPU time, because very time-consuming 3D rendering process takes the rest - 95% CPU time. This paper describes an approach for creating minimal boat simulator models that satisfy the mentioned requirements. Besides, this approach can be used for other watercraft models of this kind.