Garboard plank is a term most commonly used in boat-building. It refers to the first plank of the boat's hull, which is located on the centerline of the boat. In some regions, this plank is also known as the keelson plank or keel plank, as it runs along the boat's keel and provides a strong base for the rest of the hull. Other possible synonyms for garboard plank include the bottom plank or stem plank, as it is situated at the bottom of the boat's structure and helps stabilize the boat against the waves. In short, while "garboard plank" is the most common term for this boat-building component, there are various other words that can be used to refer to the same area of the hull.