The gunwale, pronounced “gunnel,” is the upper edge of a vessel’s side — the structural line where the deck meets the side shell plating.
Where the Name Comes From
The term dates back to old sailing warships, where guns were mounted along this upper edge of the hull — “gun” plus “wale” (a nautical term for a strengthened plank or structural edge along a ship’s side). The name has persisted in maritime vocabulary long after the original gun-mounting purpose disappeared.
Structural Role
The gunwale is a genuinely important structural zone — it’s where significant stress concentrates as the deck structure and side shell structure meet, requiring careful structural design and reinforcement at this junction (sometimes as part of the sheer strake, the topmost row of side shell plating).
Practical Use of the Term
On smaller vessels and boats, “gunwale” is used casually to describe the top edge of the hull generally (as in “water coming over the gunwale”). On larger merchant ships, the term is used more precisely in structural and technical contexts, referring specifically to the deck-edge structural connection.
Exam Relevance
Gunwale structure and its role in the deck-edge structural connection are covered within broader Ship Construction topics in deck and engineering officer competency exams.