Lightering

Prior to the 19th century introduction of steamships too large to enter some of the ports they intended to serve, in which case lightering became necessary to reduce the vessels' draft sufficiently to enter the port, cargoes ranging from water to ships' stores (food, livestock, misc.

Dredging, advances in dock construction, and containerization have reduced the frequency of the practice in dry bulk shipping since the middle of the 20th century.

However, the practice remains in common usage in the oil tanking industry ("wet" cargo trade).

The product is typically transferred using specialized hoses which offload cargo from the larger vessel to the smaller.

In many developing nations, such as China and especially India, dry bulk vessels still often lighter so they can meet draft restrictions at ports with no natural deep water access or without channels dredged to sufficient depth to allow safe transit.