Draft Survey Services

The Draft Survey is a well-established method based on Archimedes’ Principle, used to determine the weight of cargo loaded onto or discharged from a vessel by calculating the changes in the vessel’s displacement.

At USAMS – Unique Solution Association for Marine Surveying, we have extensive experience in conducting Draft Surveys for shipowners, charterers, traders, cargo interests, and other stakeholders. Our commitment to accuracy, professionalism, and independence ensures reliable results that support commercial transactions and protect our clients’ interests.

To achieve the highest level of accuracy, our surveyors utilize calibrated equipment and follow internationally recognized procedures and industry best practices throughout the survey process.

Our attendance normally commences upon the vessel’s berthing, where draft marks are jointly read and verified. Water samples are taken at the time of draft readings to determine the actual water density, which is a critical factor in the calculation process.

All deductible weights onboard, including ballast water, fuel oil, diesel oil, lubricants, and fresh water, are carefully measured and calculated based on the vessel’s hydrostatic data and tank calibration tables. Appropriate corrections are applied for trim, list, and hull deflection (hog and sag), ensuring the highest possible degree of accuracy.

Upon completion of loading or discharging operations, final measurements are taken and all calculations are verified. A detailed Draft Survey Report is then issued, providing a complete record of measurements, calculations, corrections applied, and the final cargo quantity determined.

Our Draft Survey Services Include:

Initial Draft Survey

Determination of the vessel’s displacement and cargo quantity prior to the commencement of loading or discharge operations.

Intermediate Draft Survey

Verification of cargo quantities during ongoing loading or discharging operations to monitor progress and operational performance.

Final Draft Survey

Final determination of the cargo quantity loaded or discharged upon completion of operations.

Loading Draft Survey

Independent verification of cargo quantities loaded onto the vessel.

Discharge Draft Survey

Independent verification of cargo quantities discharged from the vessel.

Cargo Quantity Verification

Accurate determination and confirmation of cargo quantities for commercial and operational purposes.

Ship/Shore Figure Reconciliation

Analysis and comparison of vessel and shore figures to identify and explain quantity discrepancies.

Cargo Quantity Certification

Issuance of independent certificates confirming the quantity of cargo loaded or discharged.

Why Choose USAMS?

Experienced and qualified marine surveyors
Independent and impartial quantity verification
Compliance with international standards and industry best practices
Accurate calculations using calibrated equipment
Detailed reporting with full transparency
Reliable support for shipowners, charterers, traders, and cargo interests
Our Commitment

USAMS is committed to delivering accurate, transparent, and dependable Draft Survey services that provide confidence in cargo quantity determination, reduce the risk of disputes, and support efficient maritime and commercial operations worldwide.