The influence of skew axes of the connecting shafts of marine aggregates on the efficiency and reliability of ship power plants is investigated. The reasons for the occurrence of centerings of axes of connecting shafts of marine aggregates are considered and their classification is offered. Failures of ship power plants are classified according to their impact on the efficiency of the installation (according to the consequences), according to the methods of their elimination, and by their nature and are divided into the groups according to the classes. It is shown that during operation, in the conditions of axial skew, traditional designs of the toothed clutch are characterized by non-uniform distribution of forces between pair of gears, which leads to their overload and, as a consequence, reduced load capacity, increased contact stresses, deterioration of lubrication surfaces of gears, increase in power consumption for friction, reduction of efficiency and deterioration of vibroacoustic characteristics due to shock load of gear. Ways to increase the efficiency of ship power plants by providing parameters of reliability of the main power plants by eliminating the negative impact of the centering axes of the connecting shafts of marine aggregates through the use of compensating devices are considered. It is proposed to use as compensating devices, the design of high-efficiency clutch, which in the conditions of axial skew, are characterized by a more uniform distribution of forces between pair of gears than existing ones, ie work almost as a perfect hinge. Regarding the proposed toothed couplings, a previously unknown objectively existing property of the toothed clutch operating at the skew of the axes of the connecting shafts is established, which is that under a certain nonlinear law changes in the generating side surfaces of the outer teeth evenly between all conjugate pairs of teeth. The use of a high-efficiency clutch in the ship power plants is considered and the basic and functional (structural) scheme of the main marine aggregate with a series connection of elements is made to assess the impact on reliability parameters.