What is Marine Engineering?

Marine engineering is the operation, maintenance and monitoring of mechanical systems aboard marine vessels, including boats, ships and submarines. This profession involves the application of different engineering fields, including computer science, electrical engineering, electronic engineering, and mechanical engineering.

Marine engineers will typically have studied marine engineering and are responsible for some or all major mechanical and engineered systems aboard a vessel. These could include systems related to electricity generation, propulsion, fuel, air conditioning, lighting, water distillation, lubrication, electrical and electronic components, and more. 

With working locations including aboard ship, engineers in this profession will typically need to be able to work at sea, including for long durations according to the requirements of their role or employer.

Marine engineering is sometimes used as a catch-all to include other, related, engineering disciplines, including ocean engineering and naval architecture – which we will cover in more detail in the ‘related fields’ section, below.

What Do Marine Engineers Do?

Excluding any work done in the related fields, marine engineers are responsible for the operating, monitoring and maintenance of mechanical systems aboard sea-going vessels.

The work of a marine engineer is similar to that of other engineers in that it will involve the maintaining of mechanical systems under their control to ensure they are operating correctly. This work involves record-keeping and maintenance planning as well as dealing with emergency breakdowns and repairs. As a marine engineer, you may work as part of a larger team of engineers, possibly under the management of a chief engineer.

Of course, working at sea adds a different dimension to this profession as these engineers may also be involved in tasks such as fuel oil bunkering, where fuel oil is transferred from a bunker station or barge to a larger ship.

In addition, the ocean environment also brings particular challenges for marine engineers, including saltwater corrosion, hydrodynamic and hydromechanical forces, extremes of temperature, and the remoteness of some project locations.

Marine engineering was revolutionised with the arrival of propulsion methods for vessels in the latter half of the 19th Century, transforming the work from that of a ‘stoker’ on steam ships to full marine engineers as technology developed.

The technological advances continue to this day, with the introduction of technologies such as fuel cells. Aside from managing the operation and maintenance of machinery aboard sea-going vessels, marine engineers also oversee areas such as:

1. Anti-Fouling

This involves the removal of marine organisms that could obstruct essential parts and components. This can be done through electro-chlorination, where the high electrical currents are passed through seawater, changing the chemical composition of the water and purging any bio-matter. Electrolytic methods of anti-fouling involve an electric current running between a copper and an aluminium anode. The copper releases its ion into the water, creating a toxic environment that will kill off bio-matter while the aluminium coats the inside of pipes to prevent corrosion (see below). Other techniques, to remove mussels and algae from the hull of a vessel, for example, include special paints that prevent these organisms from attaching themselves and growing.

2. Cavitation

Cavitation occurs when an area of low pressure causes an air bubble to form in liquid. The low pressure lowers the boiling point of the liquid so that it vaporises into a gas, which can in turn cause damage to pumps and other components. Cavitation can also take place on the surface of a propeller, creating a small, violent implosion that can damage the blade. Using more blades allows for a lower number of revolutions to deliver the same rate of propulsion without the risk of cavitation. The use of multiple blades is particularly useful for submarines, allowing them to achieve propulsion while staying quiet.

3. Corrosion

Marine engineers need to address the problem of surface corrosion as a result of the seawater environment. This can be addressed with cathodic protection, where other metals are used as a sacrificial anode that corrodes instead of the hull, or through sending a low DC current the hull to alter the electrical charge and delay the onset of electro-chemical corrosion.

4. Emissions

Marine engineers may be responsible for managing emissions from vessels to prevent them from raising atmospheric and ocean acidity, which can harm marine life.

5. Hydrodynamic Loading

Just as civil engineers need to take account of wind loads, marine engineers also need to assess the effects of wind and waves buffeting a ship or submarine.

6. Oil and Water Discharge

Oil, water and other substances collect at the bottom of a ship. Known as ‘bilge,’ this mixture of substances needs to be pumped overboard but needs to pass a threshold test of 15 parts per million before it can be discharged. Engineers test this bilge water and separate the oil from the fluids until they pass the test and can be discharged from the vessel.

7. Stability

Naval architects (see below) are concerned with designing vessels that are able to remain stable against the forces of water and air. However, it is the job of marine engineers to ensure this stability is maintained when cargo is added. High stacks of containers will not only increase the mass of the vessel, but will also raise the centre of gravity. Fuel can also cause an imbalance as the liquid pitches and shifts. This can be counteracted by using water in ballast tanks to offset the weight of the fuel. 

Related Fields

There are a number of fields related to marine engineering. Some of these can be confused with the work of marine engineers, others require the assistance of marine engineers, and some of these fields are sometimes bracketed under ‘marine engineering.’ These related fields include:

1. Civil Engineering

While not directly associated with marine engineering, civil engineering concepts are a key part of designing the infrastructure of shipping – such as bridges, ports, and tunnels. These concepts play a vital role in ocean engineering (see below), which is frequently included as an aspect of marine engineering.

2. Electrical Engineering and Robotics                       

Marine engineering may incorporate aspects of these disciplines, for example, when undertaking tasks using unmanned underwater vehicles (UUVs) or laying underwater cabling.

3. Mechanical Engineering

Marine engineering is closely related to mechanical engineering, as mechanical engineers are responsible for the design of many shipboard systems, including propulsion plants, steering, ventilation, cargo handling, anchoring, electrical power and exterior communication. Marine engineers will, meanwhile, be responsible for the installation, operation, maintenance and monitoring of these systems. Marine engineers require an understanding of many mechanical engineering topics including fluid dynamics and mechanics, structural mechanics, material strengths, and more.

4. Naval Architecture

Naval architects are concerned with the design of vessels and their means of propulsion. Although naval architects and marine engineers may work alongside each other, the difference is that naval architecture is concerned with design engineering – often with computer aided design programs – while marine engineering is focused upon operations.

5. Ocean Engineering

This area of engineering is often placed under the umbrella of ‘marine engineering’ – especially outside of the United States. However, it is distinct in that, where marine engineering is concerned with shipboard systems, ocean engineering is concerned with structures and systems adjacent or in the ocean itself. Ocean engineering projects include offshore platforms, wave energy systems, underwater life support, harbours, piers and more. These include offshore drilling operations and oil rigs. Marine and ocean engineering are concerned with many similar engineering disciplines, such and hydrodynamics and mechanics.

6. Oceanography

This scientific field is concerned with the gathering and analysis of data related to the ocean. Marine engineers use this data to inform their work.

Types of Marine Engineering Jobs

Although people have taken to the seas for thousands of years, modern marine engineering systems date back to the First Industrial Revolution and the development of steam-powered engines. A blacksmith, Thomas Newcomen created a steam-powered engine to pump water from mines in 1712 and, in 1807, Robert Fulton used a steam engine to turn a wooden paddle that propelled a ship through water. This was the beginning of marine engineering, with steam-powered paddle steamers growing in size and use until they were superseded by more modern technologies.

The most common jobs for marine engineers are working aboard vessels in either the merchant or armed navy. However, marine engineers can also find work in manufacturing for shipping equipment and machines or as teachers and tutors in training institutions. 

Where Do Marine Engineers Work?

As noted above, most marine engineers will find work aboard vessels, depending upon your training, expertise and interests these can include everything from aircraft carriers and tankers, to container ships, passenger vessels, and even tugs or barges. Whether working for the coast guard, trading, or the military, life on board ship can be physically and emotionally demanding.

Marine engineers may work alone or in teams inside an engine room, depending on the size of the vessel. Work is usually split into shift patterns, although there may be additional maintenance requirements and these engineers will be required to help if there is an emergency.

Most marine engineers are employed to work as part of a ship’s crew on a contract basis, with different contract lengths and rates of pay depending on experience and rank.

The requirement for marine engineers is expected to continue growing, mainly as a result of the dependence of global markets on shipping, with a full 80% of the world’s trade by volume (and 70% by value) using ships. 

How to Become a Marine Engineer

Most marine engineers will have a bachelor’s degree in marine engineering, marine systems engineering or marine engineering technology. However, a university engineering programme is not the only route into this profession, as others may take an apprenticeship or work towards the role from another profession. Whichever route you take, practical training is invaluable and will help you get a job once qualified.

Apprenticeships and university degree courses will have their own specific entry requirements according to institution or company and location, but it is possible to join an organisation like the Merchant Navy or Royal Navy and work towards a marine engineering degree while there.

Many shipping companies provide sponsorship for trainees, meaning you can study for a qualification with a top nautical college and gain valuable work experience, all while your university tuition fees are paid for you.

Finishing a relevant degree course is not the end of the journey, but rather a first step into your career as you will usually begin as a junior engineer to be build up experience. Then, you can begin to work your way up from being a fifth engineer through the ranks of fourth, third and second engineer to become a chief engineer. 


In order to progress through this career, as with many other engineering careers, you will require certification.

Certification is used to show your skills, knowledge and experience and is gained by passing exams at different stages of your career. In the case of a marine engineer, you may need to pass different classes of exam to move through the ranks. So, for example, you would need to pass a Class IV exam to become a fourth engineer and a Class I exam to become chief engineer.

There are a number of professional institutions for those working in marine engineering and related fields who can assist with guiding and supporting you through your career development and certification. These include:

  • The Society of Naval Architects and Marine Engineers (SNAME) – a global organisation, founded in 1893
  • The American Society of Naval Engineers (ASNE)
  • IEEE Oceanic Engineering Society
  • IMarEST
  • The Indian Maritime University
  • The Kunjali Marakkar School of Marine Engineering
  • The Marine Engineering and Research Institute
  • The Royal Institution of Naval Architects (RINA)
  • The Society for Underwater Technology 

Skills and Knowledge

The skills and knowledge required for a marine engineer include academic knowledge of maths, knowledge of engineering science, technology and physics as well as the practical skills required for the use, repair and maintenance of machines and tools.

In addition, you will need good communication skills to work with others, problem solving, critical thinking and reasoning skills and be able to pay attention to detail. You will also often require design and I.T. skills. 


Marine engineers work to operate, maintain, monitor and repair mechanical systems aboard all manner of marine vessels. Typically working in either the merchant navy or the military, these professional will either work alone, or more often in teams with other engineers.  Marine engineers use much of the knowledge associated with other fields of engineering – particularly mechanical engineering – but also need to consider the unique challenges associated with the marine environment.

It is important, therefore, for marine engineers not only to be knowledgeable in engineering matters but to also be aware of issues and laws relating to environmental protection and safety. Marine engineering can be a physically demanding job that requires being able to work in all weathers and spend time away from home.

However, not all marine engineers spend their careers aboard ships as you may also be employed to use your knowledge and experience to assist with marine manufacturing, for training others or for consultancy work in related fields such as ocean engineering or naval architecture. 


Is Marine Engineering a Good Career?

Marine engineering is a good career as it offers you real responsibility from the outset yet also provides plenty of space to learn and grow in your career. Of course, one of the biggest benefits is that you will have the opportunity to travel while getting paid for it and, with experienced engineers commanding good wages, the earnings can be very attractive. In addition, you will learn lots of transferable skills that you can take with you even if you decide to move into a more land-based career!

Is Marine Engineering Hard?

Marine engineering can be difficult at times, requiring knowledge and commitment to pass the required exams and to continue progressing your career. Plus, there is the fact that most marine engineers need to be physically and mentally tough enough to cope with working at sea. However, for those who have the necessary qualities, marine engineering can provide a rewarding career with a strong sense of camaraderie.

Is Marine Engineering in Demand?

With the oceans covering over three quarters of the Earth’s surface and the fact that 80% of global commerce is transported by sea (or 70% by value), there will always be demand for marine engineers.

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