[Gasworld/October 7, 2025] South Korea’s Hanwha Ocean has completed what it claims is the world’s first ship-to-ship transfer of liquefied natural gas between vessels under sea trials.

It is being presented as a breakthrough because it reduces the environmental impact and resolves the risk of schedule delays caused by terminal congestion.

Traditionally, LNG carriers conducting gas trials must first load LNG from a terminal and later return the remaining LNG once trials are complete.

Now LNG can be directly transferred to another vessel under trial at sea, significantly improving efficiency and flexibility.

Challenges with LNG ship-to-ship transfers include technical complexity, since ships require specialist equipment and staff need training to handle cryogenic LNG at extremely low temperatures (–162°C) as well as precise pressure.

Operational risks include thermal shock, ice build-up, and the potential for leaks or equipment damage.

Additionally, strict regulatory compliance for varying international and local laws, along with ensuring crew expertise, is paramount for safe and efficient operations.

But anything which can add flexibility is likely to be welcomed by the industry, particularly as the use of LNG as a marine fuel is “rocketing,” according to certifications body DNV.