What is Bunkering in Shipping and How it Helps Your Vessel

This is how bunkering is done off shore
Off-shore bunkering

Bunkering fuel is a critical operation in the shipping industry, involving the fueling of ships with marine (bunker) fuels. With this process, vessels ensure that they have the necessary fuel to power their engines and/or includes food and drinking water supplies for the crew. In 2020, the global bunker fuel market was valued at $110 billion, highlighting its significant role in maritime logistics (source: Allied Market Research). And its no surprise that proper bunkering is essential for the safe and efficient maritime operation.

What is Bunkering

In the context of maritime operations and shipping, bunkering refers to the fueling of vessels and ships with their corresponding fuels. The term also encompasses the supply of essential provisions for the crew. Bunkering can be done via pipeline or tanker vessel or through special bunker vessels on the water. Offshore bunkering, or ship-to-ship fueling outside port areas, requires safety measures to prevent fuel spills into the ocean.

The Most Common Types of Maritime Bunkering

Low Sulfur Fuel Oil (LSFO)

Low Sulfur Fuel Oil was designed to meet the current environmental regulations. Its possible to achieve that by having a reduced sulfur content. LSFO is fundamental in Emission Control Areas, where regulations obligate the fuel use by any ship to not exceed the maximum of 0.1% in sulfur content. The Low Fuel Oil definitely minimize sulfur oxide emissions, which in the long run are harmful to the environment and human health


High Sulfur Fuel Oil (HSFO)

High Sulfur Fuel Oil  contains a higher concentration of sulfur, meaning that has to be used outside any Emission Control Area. Its cheaper and cost effective than Low Sulfur Fuel Oil but everyday it become more and more restricted due to global efforts to reduce sulfur emissions. Vessels using HSFO must often employ scrubbers to clean exhaust gases and comply with international regulations.

Low Sulfur Marine Gas Oil (LSMGO)

Low Sulfur Marine Gas Oil is the newest cleanest alternative to traditional marine gas oil. It contains lower sulfur content and it is regularly used in areas where emission standards are strict. LSMGO is compatible with most marine engines without requiring any or significant modifications. LSMGO is favored in the maritime industry for its balance between cost, availability, and environmental compliance.

Stages of Bunkering Operations

The process on a ship is divided into four main stages: preparation, performance, delivery, and wrap-up. Each stage involves specific steps to ensure safe and efficient fuelling.


Preparation is the first and crucial stage of bunkering. It involves:

  • Calculating and checking which bunker oil tanks need to be filled.
  • Transferring oil between tanks to prevent mixing incompatible oils.
  • Holding a meeting with the bunkering team to discuss safety procedures, emergency protocols, and individual responsibilities.
  • Filling out a checklist to ensure all steps are covered and no detail is overlooked.


The performance stage is the actual execution of the bunkering operation:

  • Starting with a low pumping rate to confirm oil is entering the correct tanks.
  • Regularly monitoring tank levels and adjusting the pumping rate as necessary.
  • Maintaining communication between the ship and the bunkering facility to ensure smooth operation.


During the delivery stage, the focus is on ensuring the proper and safe transfer of fuel:

  • Connecting the hose from the bunker facility to the ship’s manifold.
  • Keeping a continuous sample of the bunker fuel to check for quality.
  • Switching between storage tanks as needed to accommodate the delivered fuel.


The final stage, wrap-up, involves:

  • Air blowing the bunkering supply line to clear any remaining oil.
  • Taking final soundings of all bunkered tanks.
  • Correcting the volume for trim, heel, and temperature.
  • Signing the bunker receipt and sending samples for laboratory analysis.
  • Recording the operation in the oil record book and storing the new bunker until laboratory results confirm its quality.

How to receive Bunkering

This is how you can get a on-port bunkering service
On-port Bunkering

Bunkering can be received in various ways, depending on the location and circumstances.

At Port 

At port bunkering is carried out whenever the vessel is docked at a port. This method typically involves pipelines to transfer fuel directly to the ship’s bunker tanks. This is one of the most convenient service for vessels, because all the bunkering operation can be done while you are in a safe place that complies with all the regulations.


Offshore bunkering is also known as ship-to-ship bunkering and it occurs outside port areas, usually at sea. This method involves transferring fuel from one vessel to another. Is most used by vessels that cannot dock at port due to their size or operational schedules. High safety precautions are essential to prevent spills and ensure the smooth transfer of fuel.


The Importance of Bunkering in Shipping

Bunkering is and will be an essential operation in maritime industry, helping vessels be adequately fueled and provisioned for their journeys. By understanding the types of fuels, the stages of any operation, and the methods of receiving fuel, ship operators can optimize their efficiency, guarantee safety, and comply with environmental regulations. Proper practices will contribute to the overall sustainability of the industry.

If you are in need for expert assistance with your bunkering needs and to ensure your vessel operates at peak efficiency, explore our bunkering fuel services. Our team is dedicated to provide reliable and safe bunkering solutions tailored to your specific requirements. Contact us today to learn more about how we can support your maritime operations.

Enhancing Your Bunkering Experience

At Nolkata Marine, we take pride in delivering top-notch services that exceed industry standards. Our team of experts ensures a seamless bunkering process, from selecting the right fuel type to executing operations with precision. With our commitment to safety, efficiency, and environmental responsibility, we guarantee a superior experience for your vessels.

Learn more about our bunkering services and discover how we can optimize your maritime operations for success.