Marine engines are used to propel ships.
They can also be used to heat up seawater, to help power aircraft, and to transport large amounts of cargo.
But they are not particularly well suited to the task of powering large fleets of ships.
Marine engines rely on a chemical reaction called oxidisation to convert seawater to oil, which can be used in fuel and oxidiser.
Marine fuel requires high pressure and high temperatures.
They are not very well suited for power generation because of their low efficiency.
But diesel and jet fuel have the potential to power small ships and power submarines.
So far, there has been little research into marine engine technology.
Marine engineers, meanwhile, have developed many marine propulsion systems, which are similar to marine engines but have been adapted for power.
Marine diesel engines are usually designed to run at sub-sea depths and can generate up to 3MW of power per 100km.
They work by converting seawater into oil at subsea depths using a chemical process called oxidising, which converts seawater at high pressures into carbon dioxide and oxygen at a relatively high temperature.
A marine diesel engine is powered by a fuel injector.
The engine produces a jet of fuel, which is then pumped back into the sea and the engine continues to operate.
A diesel engine works by producing a jet in the sea by burning hydrocarbons, but the engine is not particularly efficient.
Its fuel injection system, however, makes the diesel engine more efficient than diesel engines.
The fuel injectors are used for both marine and aviation engines.
Marine gas engine: The marine gas engine is a very basic diesel engine that produces hydrogen gas by burning hydrogen.
The gas is pumped through a gas generator, and it is burned for power, but this power comes at a cost.
The cost of the fuel is lower than that of diesel.
It has a range of up to 50km.
Marine gasoline engine: A marine gasoline engine is similar to diesel in that it produces gasoline by burning gasoline.
The gasoline is burned at high pressure, and the resulting fuel is injected into the ocean.
This fuel injects into the marine environment and releases oxygen and other gases that contribute to the formation of marine carbon dioxide, a greenhouse gas.
Marine jet fuel: A Marine Jet Fuel engine is the most advanced of all marine engine types.
It produces jet fuel by burning jet fuel.
This jet fuel is released into the air.
Marine Jet fuels have a range from 40 to 150km.
These are not suitable for power applications.
They tend to have higher fuel consumption and a lower efficiency than diesel.
Marine coal engine: This is a diesel engine.
The coal is burned to produce hydrogen.
Hydrogen is a fuel that can be produced at great pressure, but it requires high temperatures and high pressure to be produced.
A Marine Coal Engine uses a combination of combustion and heat-releasing chemicals to produce steam, which drives a turbine that produces electricity.
Marine electric motor: A diesel electric motor produces electricity by burning fossil fuels.
A marine electric motor can be operated from a turbine.
The electric motor operates in a constant cycle and produces electricity at the same frequency that it is being used.
Marine hydrocarbon: This diesel is an intermediate form of marine hydrocarbon.
It can be converted into oil using an oxidising process.
The hydrocarbon is burned in the water at high temperatures, producing hydrocarbic acid.
The acid is released as water evaporates, making it less viscous.
It is not suitable to power ships, however.
Mixed fuels: Mixed fuels are different to diesel engines in that they produce both gas and electricity.
Mixed fuels have low operating temperatures and a high pressure at which they can be made.
Mixed fuel engines are suitable for marine power generation but are less efficient than marine diesel engines, making them unsuitable for power transmission.
This section summarises marine fuel technologies and is not intended to be a complete guide to marine propulsion.
It provides a general overview of marine propulsion technology.