Dockers carry out port handling operations, notably the loading and unloading of vessels. This specialism encompasses numerous duties. They can be "signalmen", giving hand or sound signals to provide coordination between the gantry operator or crane driver and the other dockers working in the hold. They are sometimes "holdmen", cleaning the holds or operating shovel loaders such as bulldozers.

Dockers also operate different types of vehicles, including heavy goods vehicles and quayside container handling trucks.