Draft Survey Expertise: Precise Ship Cargo Weight Determination

With over 25 years of industry experience, Ruswal Global Inspections provides professional draft survey services for shipping companies worldwide. Our certified marine surveyors deliver precise bulk cargo weight assessments, following international maritime standards and using state-of-the-art equipment for accurate results.
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All You Need to Know About Draft Surveys

What is a draft survey?

A draft survey is a marine procedure used to precisely calculate the weight of bulk cargo—such as Steel products, scrap metal, or grain—being loaded onto or discharged from a vessel. This process is grounded in Archimedes' principle, (A submerged object experiences an upward force equal to the weight of the fluid it displaces). By measuring the ship's draft—the vertical distance from the waterline to the keel—before and after the cargo transfer, the draft survey determines the change in the vessel’s displacement and accurately determins the cargos weight. To guarantee accuracy, adjustments are made for factors such as ballast water, fuel, and other consumables.
Widely recognized for its cost-effectiveness and reliability, the draft survey minimises discrepancies in cargo weight calculations and ensures compliance with international maritime standards.

Why choose Ruswal Global for Draft Surveys?

Experienced Surveyors: Our draft surveyors at Ruswal Global have significant expertise conducting draft surveys on a variety of vessel types and cargoes.
Precise results: We use cutting-edge equipment and software to provide reliable and accurate results
Global Standards: Our draft surveyors are aware of and adhere to international standards and regulations.
Hassle-Free Process: We know your time is valuable. Our draft surveyors work quickly and quietly, blending into your day-to-day activities, without slowing things down or getting in the way.
Comprehensive Reports: We supply the client with extensive, easy-to-follow reports with the crucial information you need to verify the weight of your bulk cargo, and make quick and informed decisions.

Our draft surveyors carry out precise measurements, which are entered into Ruswal Global’s proprietary reporting system. Using internationally standardised draft survey protocols, we calculate cargo weight for loading or discharge. All calculations are manually cross-checked for accuracy. The final report includes all survey data and can be used for quantity certification. Copies are issued to the vessel and client, providing a reliable record for operations and regulatory compliance.

Don’t leave cargo weight to chance!
Contact us today to discuss your draft survey needs.

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Services
Loading Supervision
Discharge Supervision
Pre-Shipment Inspection
Container Inspection
Sampling and Testing
Pre-Purchase Inspection

Cargo Inspection
Scrap Metal Inspection
Steel Products
Food Products
Fertilisers
Fuels
Grain
Paper
Coal
Machinery

Marine Survey
Draft Survey
Bunker Survey (BQS)
Condition Survey
On/off hire
Hatch cover testing
Ship Superintendency

Glossary of terms related to our services

Certifications
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Contact Us

+31 108 90 65 29
+44 204 577 09 29
ruswal@ruswal.org

Draft Survey FAQs

Q: What is a draft survey?
A: A draft survey measures a vessel’s displacement before and after cargo operations to calculate the weight of cargo loaded or discharged. It is an essential cargo inspection service for shipowners, charterers, and port authorities.

Q: Why choose Ruswal Global?
A: Our experienced draft surveyors use accurate hydrostatic data, verified ballast conditions, and digital readings of draft marks to achieve precise cargo measurement results within ±0.5% of total weight.

Q: What factors affect a draft survey?
A: Water density, vessel trim, ballast condition, and draft mark visibility can all impact results. Our surveyors record corrections for trim, list, and density to guarantee accurate cargo calculation.

Q: Where do we perform surveys?
A: Ruswal Global performs draft, bunker, and on/off hire condition surveys at ports worldwide, including Ghent, Rotterdam, Calais, Antwerp, and other major loading terminals.

Q: What is a bunker survey?
A: A bunker survey measures the amount of fuel oil and diesel on board a vessel at the start or end of a charter period, ensuring transparency and avoiding disputes.

Q: What reports do clients receive?
A: Each draft survey report includes recorded drafts, ballast and density data, and final displacement calculations. Reports are accepted by cargo owners, receivers, and shipping agents as evidence of cargo quantity.

Q: How long does a draft survey take?
A: Normally between 2 and 3 hours, depending on vessel size and loading conditions. Our surveyors work efficiently and without disrupting ship or terminal operations.

Q: Do you follow international standards?
A: Yes, our draft and bunker surveys follow IMO guidelines and international maritime standards for cargo measurement and loss control.

Q: What other services do you offer?
A: Ruswal Global also performs cargo loading and discharge supervision, bunker quantity surveys, on/off hire inspections, and loss control surveys for bulk and liquid cargoes.

Q: Why is accuracy important?
A: Precise draft surveys help prevent claims, verify cargo quantity, and protect both shipowners and cargo interests during transfer or sale of goods.