Lighterage
Use of barges or smaller vessels to discharge cargo from a deep-draft ship at anchor where the destination port cannot accommodate her draft.
In practice
Common in the US Gulf for VLCC discharge to refinery-bound smaller tankers, and at certain Asian draft-restricted terminals. The lightering vessel arrives alongside underway or at anchor; senior STS coordinator runs the operation.
Regulatory detail & full definition
Lighterage is the use of barges or smaller vessels to transfer cargo to or from a deep-draft ship lying at anchor, where the destination port cannot accommodate the mother ship's full draft. It is common for Capesize coal and iron-ore cargoes at shallower importing terminals, such as on the Indian east coast, and for crude oil it takes the form of routine ship-to-ship lightering at designated offshore zones (for example the US Gulf's LOOP and the US Atlantic STS areas). Lightering operators supply mooring masters or STS coordinators, fendering and hose-handling teams.
Related
Source: Industry usage; OCIMF STS Transfer Guide
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