Draft survey

A draft survey is a standard maritime method used to calculate the weight of bulk cargo loaded or discharged from a vessel. It is widely used for commodities such as coal, iron ore, grain, cement, fertilizers, minerals, and other dry bulk cargoes where an accurate determination of cargo quantity is essential for commercial and operational purposes.

The draft survey process is based on measuring the vessel’s draft before and after cargo operations. By carefully recording the vessel’s drafts at designated points and considering factors such as seawater density, ballast water, fresh water, fuel, lubricants, stores, and other onboard weights, the surveyor can determine the vessel’s displacement. The difference between the calculated displacement before and after cargo operations provides an accurate estimate of the cargo quantity.

A professional draft survey requires experienced surveyors, accurate draft readings, proper density measurements, and careful consideration of the vessel’s hydrostatic data. Readings are normally taken at the forward, aft, and midship draft marks, with corrections applied where necessary for vessel trim, density variations, and other relevant conditions. The surveyor then compares the calculated figures with the vessel’s stability and hydrostatic information to establish the final cargo quantity.

Draft surveys play an important role in preventing cargo quantity disputes between shipowners, charterers, shippers, receivers, terminals, and other parties involved in the cargo operation. A properly conducted survey provides an independent and documented assessment of the cargo quantity and can serve as an important reference for commercial settlement, cargo documentation, and operational records.

Our professional draft survey services are carried out with attention to accuracy, transparency, and proper maritime surveying procedures. From initial draft readings to final calculations and reporting, every stage is carefully monitored to provide reliable cargo quantity figures and minimize discrepancies during loading and discharge operations.

Whether required before loading, after loading, before discharge, or after completion of discharge, a draft survey provides valuable information for determining the actual quantity of bulk cargo handled by the vessel. Our experienced marine survey team can support shipowners, charterers, cargo interests, traders, terminals, and ship agents with reliable draft survey services at ports and anchorages.