This article considers the characteristic features of the electric-energy systems of the dynamicpositioning drilling vessels Stena Drillmax of Samsung Heavy Industry dockyard, Discoverer Clear Leader of DSME-DAEWOO shipbuilding and Marine Engineering dockyard, and Pacific Scirocco of Maersk Viking dockyard. The electric-energy systems of the drilling vessels include four to eight generator sets connected to the main electric switchboards located in isolated machine compartments separated from each other by watertight and fire-resistant bulkheads to increase the survivability. The propulsion system includes, as a rule, six azimuth thrusters with semiconductor frequency converters. The main ways in which modernization is carried out of drilling-vessel electric-energy systems are to ensure the operation of the vessel power plants on a common bus without reducing the reliability of the power supply of the positioning system and realizing the idea of the split power islands in the electric-energy system using a modernized monitoring and protection system for diesel generators (AGS, AGP blocks), a system of electrical distribution, and a more efficient algorithm of functioning of the PMS automation system, which in the case of the accident allows localizing the emergency area within one main switchboard without deenergization.