Ship-to-ship transfer
STS
Meaning
A ship-to-ship (STS) transfer moves cargo directly between two tankers moored alongside each other, at anchor or under way, instead of via a terminal.
Also written as STS transfer
Ship-to-ship transfer explained
STS transfers are used to lighten large ships for shallow ports, to combine or split cargoes, and to move cargo where no terminal is available. They are planned under industry guidance from OCIMF and ICS and need fenders, hoses and an experienced mooring master.
Charter parties should say whether STS is allowed, where, and who pays for the extra insurance, equipment and time. STS in some areas also carries sanctions-compliance risk that charterers and owners now check closely.
Related terms
Lightering
Lightering is transferring part of a large tanker's cargo to smaller ships so it can enter a port too shallow for it fully laden.
Sanctions clause
A sanctions clause allocates the risk of sanctions: the owner can refuse orders exposing the ship to sanctions, and the charterer warrants it will not give them.
SPM
A single point mooring (SPM) is an offshore buoy a tanker moors to and loads or discharges through, connected to shore by subsea pipelines.