Apparatus for transferring cryogenic fluid from a first vessel (5) to a second vessel in an offshore environment. The apparatus includes a semi-submersible floating dock with variable buoyancy structure (14, 15) operable to alter the draught of the dock, enabling it to be lowered in the water and raised again to engage the dock with the second vessel. A single point mooring system (3) is attached to the dock. At least one rigid cryogenic pipeline is attached between the first vessel and the dock via flexible connections. A structure (12) for transferring cryogenic fluid from the dock to the second vessel.