Performing a thorough bunker quantity survey (BQS) is a critical operation to ensure accurate measurement of fuel onboard vessels before and after bunkering. From my experience in maritime surveying, the accuracy of these surveys hinges on meticulous sounding and ullage readings combined with compensations for ship trim and list. The process starts with boarding the vessel to take initial measurements of bunker tanks. This involves using calibrated sounding rods or electronic sounding devices to gauge the liquid level. Simultaneously, temperature readings are noted because bunker fuel density changes with temperature, and accurate calculations require density correction to standard conditions. After gathering these pre-bunkering figures, the bunkering operation is closely monitored. Crew coordination is vital as hoses are connected to the manifold, and the bunker barge transfers fuel into the vessel's tanks. Documentation, such as logging operations in the ship's logbook, helps maintain transparency and traceability. Post-bunkering, the surveyor takes readings again, noting any overflow or changes in the ship’s condition, such as trim and list adjustments caused by fuel redistribution. These factors affect the volume and must be mathematically accounted for when calculating the net bunker quantity added. By carefully following these steps and applying standard correction formulas, marine surveyors ensure that bunker quantity measurements are precise, preventing disputes and contributing to safe, efficient maritime fuel management. Incorporating digital tools and maintaining thorough records enhance accuracy and reliability in every bunker survey I have performed.