gunwale

The gunwale, also spelled gunnel, is the upper edge of a boat's hull, running along the side at the top of the vessel. It defines the intersection of hull and deck and often forms a visible line around the boat. On many craft the gunwale is reinforced with a cap rail or a protective rub rail to resist wear from lines, docks, and water spray.

Construction and variations: In wooden boats the gunwale is typically a thick plank or built-up edge. In contemporary craft it may be an integral part of the hull or a separate rail made of metal, fiberglass, or composite materials. Some vessels have inner and outer gunwales, with fittings such as cleats, chocks, and lifelines mounted along the rail. A rubbing strake or rail along the gunwale provides added abrasion resistance.

Function: The gunwale helps protect the hull from damage during docking and handling, provides mounting points for equipment, and offers a handhold or seating edge for crew and passengers on small boats. It can also help shed water away from the interior by directing spray outward and away from the deck.

Etymology and usage: The origin of the term is uncertain. Gunwale is the standard spelling in most modern usage, with variants such as gunnel found in some dialects or historical texts.