Final answer:
The gunwale is located on the upper edge of each side of the boat, providing reinforcement for the boat's structure and a place to grip or tie down equipment.
Step-by-step explanation:
The gunwale is a crucial component of a boat's structure. Located on the upper edge of each side of the boat, the gunwale serves multiple purposes. It helps to reinforce the boat's structure and provides a place for the crew to grip or tie down equipment. When thinking about the safety and integrity of a vessel, the gunwale plays a significant role. However, in the case of events such as a 'tremendous plosion' that causes the boat to list violently, the stability and structural integrity of the gunwale, along with other parts of the boat, can be crucial for the safety of those on board.