We've already seen electric motorboats and even ferries, but a considerably larger battery-electric vessel should soon be in operation. It's called the e5 tanker and interestingly enough, it will be used to deliver conventional fuel to other ships.
The 62 meter-long (203-ft) vessel is being developed via the Japanese e5 Project, which is a consortium of shipping and maritime technology companies. Project partner Asahi Tanker has placed an order for the first two tankers, which will be used for fuel delivery in Tokyo Bay. Kawasaki Heavy Industries is designing the propulsion system.
Each 499-ton (453-tonne) ship will incorporate two 1,740-kWh Orca ESS lithium-ion battery packages made by Corvus Energy, for a combined capacity of 3,480 kWh – or 3.5 megawatt-hours. Those packs will power the motors of two 300-kW azimuth thrusters, delivering a cruising speed of about 10 knots (19 km/h or 12 mph). Battery range per charge is presently described simply as "many hours."
Not only will the e5 produce no exhaust emissions, but its smooth-running electric motors should reportedly create fewer vibrations and less noise than traditional engines, making onboard conditions more comfortable for the crew. Additionally, in the event of a natural disaster in the Tokyo Bay region, the ship can provide electricity to emergency services.
The two tankers are currently in the process of being constructed by KOA Industry Co. Ltd. and Imura Shipyard. Plans call for the first vessel to enter service sometime next year, with the second to follow in 2023.
Sources: Corvus Energy, e5 Lab, Kawasaki, Asahi Tanker via IEEE Spectrum
That is why all countries need to start producing biodiesel fuel at large scales (using all kinds of waste/biomass/trash/sewage):
https://en.wikipedia.org/wiki/Biodiesel