Draft survey

With a draft survey, we can determine the weight of cargo on board the vessel by measuring the displacement of the water before and after (un)loading. The resulting difference represents the weight of the designated cargo. A survey is performed by reading the vessel’s draft markings at six standard points on the hull: forward, midship, and towards both the port and starboard sides. Revisions for factors such as trim, water density, and non-cargo weight (such as fuel oil and drinking water) are part of the calculation that we perform. The accuracy of a weight determined by draft survey also depends upon the sea conditions (pitch and swell) at the time of loading or discharge.

Strengths of this service

We use our inspection and supervision expertise to support our clients. With a global presence in more than 80 countries, we offer you an unparalleled perspective to ensure sustainable added value.

  • A survey is performed by reading the vessel’s draft markings at six standard points on the hull: forward, midship and towards both the port and starboard sides

  • Revisions for factors such as trim, water density and non-cargo weight (such as fuel oil and drinking water) are made before calculating the cargo weight change

Draft survey

Our highly-qualified professionals have extensive experience in this service and are available 24/7 to perform a draft survey and produce an independent report using the Control Union Draft Survey Software System, based on the internationally standardized draft survey protocol. This program calculates the loaded or discharged weight and a signed quantity agreement will be handed over to the chief officer with the draft survey report sent to the relevant parties.

When draft surveys are initiated by independent surveyors, cooperation of the ship’s officers is essential. Independent surveys should be undertaken together with the vessel’s chief officer and chief engineer or their appointed deputies, during the relative survey sections.

Industries we work in

We perform our inspection services in the following industries:




Biomass and biofuels

Coal, minerals and iron ore




(Precious) metals

Molasses and vegetable oils


Fly ash, lime, cement and sand

Waste and recycling

grain silo commodity inspections

How can we help you?

Do you want specific information on our Commodity Inspection services? Or would you like to have a quotation? Do not hesitate to contact us or find your nearest local office.