A gaff hook is a long pole with a hook on one end for spearing fish. Pirates often add extra, heavier hooks to both ends of gaff hooks to assist with boarding actions. After the pirates use grappling hooks to draw ships close together, they hook the gunwales together with boarding gaffs to prevent the ships from drifting. Small crafts often use boarding gaffs in place of grappling hooks.
Boarding gaffs bite deeply into the wood of the railing.
The gaff can also be used for fishing when not in combat.