Increasing fuel costs and regulation of emissions are encouraging operators, shipbuilders and researchers to seek improvements in marine vessel efficiency. In the area of vessel electrical systems, there are increasing choices as a result of research and development over the past decade giving rise to a number of promising new technologies. Promising new battery chemistries are being developed and existing chemistries are being enhanced with nano-technology. Supercapacitors and fuel cells are now powering ferries. Permanent magnets are enabling novel motor topologies and solar panel prices are decreasing. In addition to new technologies recently commercialised for vessels, new developments in electric vehicles and grid electrical systems will be applicable to the marine environment. This article reviews emerging electrical technologies and it focusses on those with potential for improving vessel efficiency within the next decade.