Key takeaways
- Preserve the reference point and measurement record.
- Leave quantity conversion to the appropriate verified procedure.
Keep the measurement chain intact
The commercial team receiving a cargo quantity should be able to identify the underlying measurement basis. A bare ullage number, forwarded without tank identity or supporting records, cannot explain how the final quantity was obtained.
- Identify the tank and the recorded measurement reference.
- Preserve the associated observations and calculation documents.
- Refer discrepancies to the responsible survey and vessel personnel.
If two reports use different measurement times, investigate that difference before assuming either figure is wrong. Retain the sequence of operations so the reviewer can see whether cargo movements occurred between observations.
Common mistakes
Do not subtract ullage from an assumed tank height and call the result cargo volume. Avoid combining figures from different tanks or measurement bases in one unexplained total. This glossary does not provide a tank-measurement procedure.
Where Zeaclub fits
Zeaclub offers digitalised procedures across the voyage workflow.
Zeaclub supports agentic, AI-assisted operations with a human in control.
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Educational information only; not legal, financial or trading advice. Contract wording and applicable rules control. Verify current requirements and obtain qualified advice before acting.
Frequently asked questions
Is ullage the depth of liquid in the tank?
No. It measures the distance above the liquid from the defined reference.
Does ullage directly state cargo weight?
No. Further verified conversion and cargo information are required.
Why retain the measurement time?
It helps relate the observation to cargo movements and other records.
Who should assess a measurement discrepancy?
The responsible technical and survey personnel using the relevant documentation.