Which structure provides the main support and form of the ship?

The keel is the primary structural component that runs along the bottom of a ship from the bow to the stern. It serves as the backbone of the vessel, providing essential support and rigidity to the overall structure. The keel helps to maintain the ship's shape and integrity under various conditions, playing a crucial role in its stability and performance in the water.

While the hull refers to the entire structure that forms the outer shell of the ship, including the sides and bottom, it is the keel that provides the fundamental support. The beam is related to the width of the ship and contributes to stability, but it does not offer the same foundational support as the keel. Compartments, on the other hand, are internal divisions within the hull that help with buoyancy and structural organization but do not constitute the main supportive structure of the vessel. Therefore, the keel is recognized as the most critical element in providing the main support and form of a ship.