Ship to Ship Personnel Transfers: Managing STS Operations for Safer, Smoother Port Calls

There are few operations in shipping that require more precision and coordination than a ship-to-ship personnel transfer.

Whether you’re handling crew changes, loading supervisors, or surveyors, transferring people between vessels at sea introduces a whole new set of risks and responsibilities. Getting people from one ship to another requires attention to safety, legal compliance, and scheduling.

For port agents and ship managers, ship to ship personnel transfers are high-stakes maneuvers that demand attention to detail, proper planning, and compliance with international regulations. This post breaks down what you need to know, how to reduce risk, and where Base can give your team an edge.

What Is a Ship-to-Ship Personnel Transfer?

A ship-to-ship personnel transfer happens when people are transferred directly from one ship to another. These are most common during offshore cargo operations, crew rotations, or inspections. The two vessels involved are usually large crude carriers or tankers, but transfers also happen on smaller vessels, depending on the nature of the operation.

These transfers can be carried out in an anchorage, near an offshore terminal, or even at the outer port limit. Depending on the vessels and conditions, the personnel might move via launch boat, pilot ladder, or mechanical basket.

Each method comes with safety concerns that require preparation. Strong sea conditions, shifting tides, and poor communication can lead to serious safety incidents. A ship-to-ship operation requires a thorough risk assessment, the right equipment, and a trained team.

To learn more about the mechanics and challenges of these transfers, see our guide on STS transfer.

Safety & Regulatory Considerations

Safety is non-negotiable. Every ship transfer involving personnel must comply with international regulations set by the International Maritime Organization. These rules cover everything from the physical condition of the ships involved to the type of mooring equipment and personal protective gear required.

Each vessel involved in an STS operation must carry valid certificates and maintain updated Safety Management Systems. For personnel transfers, this includes ensuring all parties are qualified and trained according to STCW standards. Documentation like the Ship-to-Ship Transfer Guide, transfer checklists, and safety declarations must be prepared and retained as part of the compliance record.

Beyond IMO regulations, local port authorities and flag states may impose additional requirements. These can include restrictions on where STS transfers can occur, required reporting timelines, or approval processes for third-party service providers. Port rules might differ depending on the cargo type, the vessels involved, or environmental considerations, so operators must verify requirements for each location and flag before scheduling a transfer.

Violations of STS regulations can lead to fines, detentions, and reputational damage. Flag states and port state control authorities may inspect documentation, crew qualifications, and safety conditions during or after an operation. Keeping transfers compliant is essential to avoid enforcement actions and to protect the company from legal exposure.

6 Operational Best Practices for Ship Agents

Agents play a crucial role in coordinating STS operations. Your job starts well before the first person sets foot on board. That means confirming the ships involved, verifying crew lists, submitting proper documentation, and managing third-party vendors like launch boats or helicopter providers. Let’s look at some best practices you can follow for transfer operations:

1. Start planning before anyone boards

Agents play a crucial role in coordinating STS operations. Your job starts well before the first person sets foot on board. That means confirming the ships involved, verifying crew lists, submitting proper documentation, and managing third-party vendors like launch boats or helicopter providers.

2. Communicate clearly with all parties

All parties involved, from the client and the captain to the local authority and the launch service, need visibility on the operation plan. Delays can lead to extra costs or missed transfer windows, so timing needs to be managed closely.

3. Account for port congestion and vessel movement

If the transfer is part of a port call, understand how port congestion can throw off your timeline. Factor this in during planning. If you’re coordinating a personnel handover during a ship-to-ship operation that also involves cargo transfers, like oil or bulk materials, you need to balance multiple workflows without conflict.

4. Always conduct a thorough risk assessment

A fresh risk assessment helps identify potential safety issues before they become real problems. Use a standardized ship transfer guide to organize the process. Having the right equipment available—including personal flotation devices, emergency lighting, and first aid kits—is critical.

5. Follow specific port and flag requirements

Port authorities and flag states may have different requirements based on jurisdiction, vessel type, and operation scope. Some may require prior approvals or safety declarations for each transfer, especially for oil cargo or when transferring personnel in open water during a port call. Double-check that your documentation aligns with both international regulations and port-specific expectations. This helps avoid delays and keeps your operations compliant

6. Keep detailed records throughout the process

Comprehensive record keeping supports both operational clarity and legal protection. Document every step: personnel boarding times, safety briefings, launch boat schedules, equipment checks, and communication logs. Save this data in a centralized system, where your team and your clients can retrieve it if questions arise during audits or invoice reviews.

Following these six practices can make a noticeable difference in how well your ship-to-ship operations run. They’re essential to keeping your team aligned, protecting crew safety, and avoiding costly delays. When the basics are handled well, everything else falls into place faster.

How Base Helps

Base gives ship agents a centralized system to manage every detail of an STS operation, from the initial request to the final invoice. Whether you’re transferring personnel, transferring cargo, or both, Base helps you maintain control.

With Base, you can:

• Create and track STS job requests, including launch boat and crew services
• Attach documents like the ship transfer guide, manifest, or risk assessment checklist
• Log transfer costs in real time and match them to purchase orders
• Communicate with vendors and vessel clients directly in the Inbox
• Track personnel involved and document each step of the process

Base’s port call software gives you visibility across all stages of a port call. If your team manages crew changes as part of larger ship transfer operations, Base helps you manage these alongside your cargo workflows without overlap or confusion.

By centralizing documents, vendor communication, and cost tracking, Base reduces confusion and helps you reduce port call turnaround time and maintain compliance during STS transfers. You can also connect Base to accounting tools like QuickBooks or Xero, keeping your financial and operational data in sync.

Conclusion on Ship to Ship Personnel Transfer

Ship-to-ship personnel transfers require strict planning, even when they appear straightforward. Every operation comes with risks, regulations, and logistics that need to be managed in real time. Port agents sit at the center of this process. Managing personnel or cargo between vessels calls for precise coordination at every step.

Staying compliant with international maritime organization guidelines, conducting thorough risk assessments, and documenting your operations from start to finish are mandatory. Base helps teams handle every step without losing track of critical details.

Want a deeper understanding of how ship-to-ship transfers fit into your larger port call workflow? Read more about port call optimization.

Key Takeaways

• A ship-to-ship personnel transfer involves transferring people directly between two ships, often during offshore operations or cargo handling.
• STS operations must follow international regulations, require the right equipment, and depend on thorough risk assessment.
• Port agents manage timing, safety, and vendor coordination. Documentation and compliance are critical.
• Base provides centralized tools to manage STS job requests, transfer costs, communications, and documentation.
• Effective use of Base supports safe transfers, reduced operational costs, and better control over port call outcomes.

Frequently Asked Questions