Ship-to-ship transfer operations, also known as STS operations, are operations where crude oil or petroleum products are transferred between seagoing tanker ships moored alongside each other at sea. Such operations can take place when one ship is at anchor or both are underway at very low speeds.

For all STS transfer operations, each Master remains at all times responsible for the safety of his ship, its crew, cargo and equipment and should not permit safety to be prejudiced by the actions of others. Each Master shall ensure that the procedures contained in this guide are followed and, in addition, that internationally accepted safety standards are maintained.

This course is a general guide to assist the shipowner/ship operator/ship personnel in preparing and executing a ship-specific Ship-to-Ship Transfer Operation Plan (STS plan), demonstrating compliance with the requirements of MARPOL Annex I, Chapter 8: “Prevention of Pollution during Transfer of Oil Cargo between Oil Tankers at Sea”, Regulations 40, 41 and 42.

It is important to stress that you always orient yourself towards your ship's specifications and follow your shipping company-approved procedures.

You will be presented with an assessment at the end of this course.

Topics in this Course

Shareable Certificate

Certificate of Completion

• Earn a Seably certificate of completion
• Download or print out as PDF to share with others
• Share online to demonstrate your new skill

Course Author

Reza KAPO

With extensive experience in maritime engineering, I bring a blend of practical sea-going expertise and academic insight to the maritime sector. Over a decade at sea, I rose to the rank of chief engineer, mentoring cadets and refining my technical skills. In addition to my sea career, I pursued advanced academic qualifications, earning a Master's Degree and a PhD in Maritime Affairs from top European universities.

Beyond academics, I have actively contributed to European maritime research projects, focusing on areas such as decarbonization, regulatory frameworks, safety, and environmental protection. Since 2017, I have transitioned into academia, where I leverage my experience to teach STCW and IMO courses to marine officers across European institutions, blending practical knowledge with academic rigor.

View courses • See full profile