The Ultimate Guide to STS Operations in Indonesia: Safety, Compliance, and Execution

Ship-to-Ship (STS) transfer allows cargo to move directly between two vessels without using a conventional shore terminal for the transfer itself. In Indonesia, however, a successful STS operation depends on much more than bringing two vessels alongside. The location, regulatory arrangements, vessel compatibility, cargo, weather, mooring setup, safety procedures, and local coordination all need to be prepared before transfer begins.

Location and Approvals

The first step is confirming where the STS operation will take place and what local requirements apply there. This is particularly important in Indonesia because STS activities may take place within port areas or other designated waters, and the applicable operational arrangements can depend on the location and type of activity.

Indonesia updated its cargo-handling framework in 2026 through Minister of Transportation Regulation No. 3 of 2026, which amended PM 59/2021. The regulation expressly recognizes cargo handling from vessel to vessel (ship-to-ship transfer) and sets out which business entities may perform cargo-handling activities.

The regulatory environment is also receiving greater industry attention. In March 2026, the Indonesian Chamber of Commerce and Industry (Kadin) brought together government institutions and industry representatives to discuss STS cargo-handling practices at Indonesian ports. The discussion covered operational governance, labor, competition, efficiency, and the need for clear rules supporting port and logistics activities. For an individual operation, the exact approvals and documentation should therefore be confirmed for the specific STS location rather than assumed from another Indonesian port.
Before mobilization, clarify:

• proposed STS location;
• cargo and quantity;
• vessels involved;
• port or local authority requirements;
• cargo-handling arrangements;
• required operational submissions;
• supporting service providers; and
• any additional requirements related to the specific cargo or location.

Local coordination should begin before the vessels reach the transfer area.

Vessel and Cargo Compatibility

Permission to conduct the operation is only one part of preparation. The two vessels must also be operationally compatible. Before the transfer, the parties should exchange sufficient technical information to determine whether the vessels can safely operate alongside each other.
Key points to review include:

• vessel dimensions and freeboard;
• manifold arrangement;
• mooring configuration;
• fender requirements;
• cargo system; and
• hose compatibility.

Cargo characteristics also affect the preparation. STS transfers can involve petroleum products, crude oil, chemicals, liquefied gases, and other cargoes depending on the operation. Each cargo may require different equipment, handling procedures, safety controls, and emergency preparations.

Current industry STS guidance covers planning and execution for petroleum, chemical, LPG, and LNG transfers, including equipment, personnel transfer, human factors, and STS safety checklists. Compatibility should therefore be established before the vessels are committed to the operation, not after they arrive alongside.

Planning and Risk Assessment

An STS operation should have a clear operational plan covering the sequence from approach through final separation. The planning process should consider the characteristics of both vessels, cargo, location, environmental conditions, equipment, personnel, and emergency response arrangements.
A typical preparation sequence may include:

Vessel information exchange → compatibility review → risk assessment → operational plan → equipment preparation → pre-transfer checks → mooring → cargo transfer → completion → unmooring

The risk assessment should consider issues such as:

• collision during approach;
• excessive mooring loads;
• hose or connection failure;
• cargo leakage or spill;
• communication failure;
• changing weather and sea conditions;
• personnel transfer;
• emergency shutdown; and
• safe separation of the vessels.

Roles should also be clearly understood before operations begin. The Masters retain their respective responsibilities for their vessels, while STS operations may also include an STS Superintendent or Person in Overall Advisory Control (POAC), depending on the operation and applicable requirements. Everyone involved should know who is coordinating each stage and how communication will be maintained between the vessels.

Weather and Equipment

Environmental conditions can directly affect whether the vessels can safely approach, remain alongside, transfer cargo, and separate. Wind, current, waves, swell, visibility, and forecast changes should therefore be reviewed before and during the operation. Mooring arrangements are equally important. Two vessels alongside can respond differently to wind, current, and wave forces, placing changing loads on mooring lines and equipment.
The operation should consider:

• vessel size and displacement;
• mooring line arrangement;
• condition and suitability of mooring equipment;
• expected environmental forces;
• fender type and placement; and
• the limits established for the operation.

Fenders protect the vessels during approach and while alongside. Cargo hoses and associated transfer equipment must also be suitable for the cargo and planned operating conditions. Industry STS guidance places particular attention on equipment such as fenders, cargo hoses, vapour hoses, and mooring equipment as part of safe transfer preparation. If conditions move outside the agreed operational limits, the operation may need to be delayed, suspended, or reassessed.

Safety Checks

Cargo transfer should not start immediately after the vessels are secured. Both sides first need to confirm that the agreed arrangements are ready.
Pre-transfer checks can cover:

• vessel moorings;
• fender position;
• cargo hose connections;
• manifold preparation;
• communication channels;
• cargo transfer sequence;
• transfer rate;
• emergency shutdown procedures;
• spill-response readiness;
• fire-fighting arrangements; and
• emergency separation procedures.

The vessels should also agree how the transfer will begin, how the rate will be increased, what conditions require a reduction or stop, and how an emergency will be communicated. Safety checks should continue throughout different stages of the operation rather than being treated as a single checklist completed before pumping begins.

Cargo Transfer

Once cargo transfer begins, conditions still need to be monitored. Cargo quantities, transfer pressure, transfer rate, vessel movement, mooring condition, hose condition, communications, and environmental conditions should remain under observation. If an abnormal condition develops, the response should follow the agreed operational and emergency procedures. This could mean reducing the transfer rate, stopping the transfer, investigating the problem, or preparing for separation.

After the required cargo quantity has been transferred, the operation moves through completion procedures. These may include stopping transfer, draining or disconnecting hoses as applicable, confirming cargo figures, completing relevant documentation, and preparing both vessels for unmooring. The vessels should separate only after the transfer equipment and vessel arrangements are ready.

Compliance and Due Diligence

STS safety is not limited to navigation and cargo handling. The identity of the vessels, cargo origin, counterparties, documentation, and trading history can also require attention, particularly for oil trades exposed to international sanctions risk. STS transfer itself is a legitimate and widely used shipping operation. However, STS has also been used internationally to conceal cargo origin or vessel activity.
Depending on the trade, due diligence may include reviewing:

• vessel identity and ownership;
• counterparty information;
• cargo origin and destination;
• Certificates of Origin and cargo documents;
• voyage history;
• Automatic Identification System (AIS) activity; and
• applicable sanctions restrictions.

Unexplained AIS gaps, inconsistent cargo documents, unclear ownership structures, or questionable cargo origins may require further investigation before proceeding. Due diligence should complement operational safety and local regulatory compliance rather than replace them.

Local Coordination

An STS transfer can bring together two vessels, cargo interests, STS specialists, equipment providers, authorities, cargo-handling parties, surveyors, and supporting marine services. In Indonesia, local coordination helps connect these requirements with the actual STS location.
Depending on the operation, the local ship agent may assist with:

• coordination with relevant local authorities;
• operational submissions and documentation;
• vessel arrival and departure arrangements;
• communication with local STS parties;
• pilotage and tug coordination where applicable;
• launch boat and personnel movements;
• surveyor or technician attendance;
• provisions and spare parts;
• crew requirements; and
• other husbandry support.

The local agent does not replace the Master’s authority or specialist STS responsibilities. Its role is to coordinate the local arrangements needed to support the operation. Early coordination is especially useful for identifying location-specific requirements before vessels, equipment, and service providers have already been committed.

STS Operations With Balancia

Balancia Ship Agency supports STS operations and related vessel requirements across Indonesia. Our role focuses on the local arrangements surrounding the operation, including coordination with relevant parties, vessel support, pilotage and tug assistance where applicable, launch boats, crew movements, technician or surveyor attendance, spare parts, provisions, transportation, and other husbandry requirements. For international vessel owners, operators, and managers, these arrangements can be prepared alongside the vessel’s STS plan so that local support is ready when required. From pre-arrival preparation through completion of the port call, Balancia provides direct local coordination for STS-related requirements in Indonesia.

People Also Ask

References

• Kadin. (2026, March 12). Retrieved from Kadin Holds FGD on Ship-to-Ship Transfer, Pushes for Loading and Unloading Regulations that Support the Investment Climate: https://kadin.id/en/kabar/kadin-gelar-fgd-ship-to-ship-transfer-dorong-regulasi-bongkar-muat-yang-dukung-iklim-investasi/
• KBLI. (n.d.). Retrieved from Regional Standard Certificate Ship To Ship (STS): https://kbli.co.id/pbumku/022000000187
• Skuld. (n.d.). Retrieved from Sanctions and STS Transfers – legal risks: https://www.skuld.com/topics/legal/sanctions/sanctions/sanctions-and-sts-transfers–legal-risks/