Slow Steaming
Deliberately sailing below design speed to cut fuel consumption, emissions and effective fleet supply.
Slow steaming is the practice of running a ship at a reduced speed to save fuel — because consumption rises sharply with speed — and thereby lower cost and carbon intensity. "Super-slow steaming" pushes this further still.
Beyond economics, slow steaming absorbs surplus tonnage: a fleet sailing slower takes longer per voyage, which tightens effective supply. It is a key lever owners use in weak freight markets and to meet carbon-intensity targets.
On The Maritime
Also known as: slow-steaming, speed reduction, eco speed.
Related terms
Bunkers
The fuel a ship burns — and, by extension, the act of taking on that fuel (bunkering). Usually the single largest voyage cost.
Carbon Intensity IndicatorCII
An IMO operational measure of how much CO₂ a ship emits per unit of transport work, graded A–E each year.
Energy Efficiency Existing Ship IndexEEXI
A one-time IMO design-efficiency standard that existing ships must meet, the in-service counterpart of the EEDI for new ships.
Time Charter EquivalentTCE
A voyage’s daily earnings net of voyage costs — the single number that makes a voyage charter comparable with a time charter rate.
Plain-English reference definition — our own explanation of a standard shipping concept, not a licensed source or legal advice. See the full glossary or the broader maritime dictionary.
Last reviewed: June 2026.