Design properties of 5 to 6 m long motor boats, having cabin and outboard engine, were developed. 14 boats made by different European producers, 2 of them Slovenian, were studied in detail. On boat shows and internet pages, data about models were collected and processed. Advantages and disadvantages were exposed. Our own ideas helped us to eliminate disadvatages, and in this way design a model better than the others. On the basis of the calculated parameters of hull, an exterior and interior design was developed. 5.5 m long boat with dynamic lines and an outboard engine, designed for 5 persons, was developed.