STS Joint Plan of Operation for the specific transfer
What is being checked
For an at-sea STS operation, the inspector is checking whether a Joint Plan of Operation was developed for the actual vessels, cargo, location and conditions, understood by the team and followed in practice. The JPO must address the agreed mooring, environmental limits, notifications, risk controls and unmooring sequence.
Ready onboard
0/9 completePractice questions
Answer aloud, then open the preparation point.
1What makes this JPO specific to the present STS operation?
Use the vessel’s approved procedures, records and fitted-equipment instructions. Demonstrate the evidence rather than giving only a general answer.
2Show the environmental limits and the action required if one is exceeded.
Use the vessel’s approved procedures, records and fitted-equipment instructions. Demonstrate the evidence rather than giving only a general answer.
3How has the risk of incendive arcing between the vessels been controlled?
Use the vessel’s approved procedures, records and fitted-equipment instructions. Demonstrate the evidence rather than giving only a general answer.
4Show the agreed mooring plan and confirm that the actual arrangement follows it.
Use the vessel’s approved procedures, records and fitted-equipment instructions. Demonstrate the evidence rather than giving only a general answer.
5Which mandatory notifications were made, and where is the evidence?
Use the vessel’s approved procedures, records and fitted-equipment instructions. Demonstrate the evidence rather than giving only a general answer.
6Explain the agreed unmooring and emergency separation sequence.
Use the vessel’s approved procedures, records and fitted-equipment instructions. Demonstrate the evidence rather than giving only a general answer.
Where an observation may arise
No company requirement exists to develop a JPO for each at-sea STS operation.
The JPO is generic or does not reflect the actual vessels, location or operation.
An officer or rating was not briefed or cannot explain relevant JPO content.
Location-specific risks or incendive-arcing controls are absent or not implemented.
Required official notifications cannot be demonstrated.
The actual mooring arrangement differs from the JPO.
The operation continued after an environmental operating parameter was exceeded.
Master's practical note
Reject a generic service-provider package until it has been checked against your vessel, the other vessel and the actual location. Before commencement, walk through the JPO with the responsible officers and station teams. If a limit is approached, everyone should know who calls the stop and what happens next; that decision should not begin with searching the document.
Equipment boundary and references
Equipment boundary: The JPO must reflect the actual mooring, fender, hose, communications and emergency arrangements. Equipment-specific steps belong in the approved operation documents and manuals.
References
- OCIMF Ship to Ship Transfer Guide for Petroleum, Chemicals and Liquefied Gases, First Edition
- Vessel STS Operations Plan
- ISM Code section 7
- Applicable coastal-state and local notification requirements
Last reviewed: 2026-08-11