A Bunker Quantity Survey (BQS) typically refers to the process of measuring and quantifying the quantities of bunker fuel, also known as marine fuel or ship fuel, that is consumed or carried on a vessel. Bunker fuel is used to power ships and is typically stored in dedicated tanks on board.

The purpose of a Bunker Quantity Survey is to accurately determine the amount of bunker fuel consumed during a specific period, such as a voyage, or to measure the quantity of fuel remaining on board at a given time. This information is crucial for various reasons, including:

1. Cost Control: Bunker fuel is a significant expense for ship operators, so accurately measuring its consumption helps in managing costs and budgeting.
2. Compliance: The quantity of bunker fuel consumed is often subject to regulatory requirements, such as emissions regulations or reporting obligations. A BQS ensures compliance with these regulations.
3. Dispute Resolution: In cases where there are disputes regarding bunker fuel quantities, a BQS report can provide an objective measurement to resolve conflicts between parties involved, such as shipowners, charterers, or suppliers.

A BQS typically involves onboard inspections and measurements conducted by qualified surveyors. They may use various methods and techniques to determine the bunker fuel quantities, such as sounding the fuel tanks, measuring density, and calculating volumes based on tank dimensions. The surveyors may also consider factors like temperature and fuel quality to ensure accurate measurements.

• Overall, a Bunker Quantity Survey is an essential process for ship operators to manage costs, comply with regulations, and resolve disputes related to bunker fuel quantities on board their vessels.