For the past 120 years internal combustion engines have powered ships. Prior to that, sailors used paddles and sail for propulsion. In the last 80 years, diesels have dominated because of their safety and reliability, which have out-weighed factors such as their inherent inefficiency (being at best 40% at optimum speed), whole of life cost (fuel and maintenance), passenger discomfort from fumes, vibration and noise and the air and water pollution they cause. Now, modem electric motors are safe and reliable. They have lower total through life costs through maintenance and fuel savings, being highly efficient (96 -98%) at all speed ranges and are quiet and are low polluters of the air and water. Current electric vessels are either very small i.e. one to 3 horsepower or very, very large where weight of the batteries is not a factor. The problem has been the weight of energy storage and energy production - how do you supply electricity on a ship? A solution is to use a combination of energies or a hybrid power system. A hybrid electric boat can use the energy available at sea in the sun and wind, and combine this with back up power from modem batteries and fossil fuel generators. Weight issues can be resolved and commercial schedules met whilst offering the additional benefit of redundancy in power supply.