The article presents a study of the relationship between passenger capacity and the main dimensions of passenger vessels-trimarans. The state of this issue has not been sufficiently studied today because there is no methodology to determine what the main dimensions of the central hull and outriggers will be and their location relative to each other along the length and width of the vessel, depending on the necessary passenger accommodation on the vessel. The field of research is the design of ships, in particular the design of passenger trimaran vessels, and the object is to determine the main dimensions of the trimaran vessel from the conditions of passenger capacity. The article reflects the architectural and design features of the trimaran vessel, depending on the location of outriggers on it. Based on the data analysis, dependencies were obtained to determine the main dimensions of the trimaran hull based on the location of a given number of passengers on it.

The article presents a method for calculating the mass load for determining the displacement of passenger trimaran vessels at the initial stages of design. The state of this issue has not been sufficiently studied to date, since there is no methodology that allows calculating the displacement of a trimaran vessel. The field of research is the design of vessels, in particular the design of passenger trimaran vessels, and the purpose is to determine the components of the mass load to determine the total displacement of the trimaran vessel. The equations of masses for trimaran passenger ships and statistical dependencies are given, as well as analytical formulas for finding the components of this equation. On the basis of a comparative analysis of prototype vessels and projected trimaran vessels, satisfactory results were obtained, which showed that the proposed methodology can be used to calculate the displacement of vessels of this type at the initial stages of design.