Independent determination of cargo loaded or discharged using vessel drafts, water density, hydrostatic data and documented calculations.
White Coral provides draft surveys for bulk carriers and other vessels where cargo quantity is determined by displacement before and after loading or discharge.
Typical Draft Survey Procedure
- Read and record vessel drafts at the required locations;
- Obtain or verify dock-water / sea-water density;
- Review hydrostatic data, sounding tables and relevant vessel particulars;
- Determine ballast, fuel, fresh water and other deductible weights;
- Calculate vessel displacement and net cargo quantity;
- Record material observations and issue a draft survey report.
The accuracy of a draft survey depends on vessel condition, sea state, draft-mark visibility, documentation, tank sounding accuracy and cooperation of the vessel. Any material limitations are noted in the report.
Attendance During Cargo Operations
Where instructed, our surveyor can attend the initial and final surveys and coordinate intermediate checks or cargo-operation observations. Draft surveys can also be combined with cargo sampling, hold inspection or other marine survey requirements.