A bunker surcharge (BAF, BSC) is an additional fee imposed by shipping lines or carriers to compensate for fluctuations in fuel prices. It is applied to the freight charges and covers the cost of fuel consumed during the transportation of goods. Bunker surcharges are calculated based on various factors such as the vessel's fuel consumption, prevailing fuel prices, and the specific trade route. This surcharge helps carriers manage the volatility in fuel costs and ensure the continued operation of their vessels while providing transparency to shippers regarding the fuel-related expenses incurred in their shipments.