What are bunks used for in relation to a boat on a trailer?

Bunks are essential components on a boat trailer designed specifically to support the boat during transport. They are positioned along the centerline of the boat and are strategically placed at crucial weight points to ensure even distribution of the boat's weight. This support helps to prevent any damage to the hull and maintains the integrity of the boat while being towed. Proper placement on bunks minimizes potential stress on the boat’s structure, helping to keep it stable and secure as it is transported on the trailer.

The other options do not accurately describe the function of bunks. For instance, bunks are not intended to stabilize the boat in rough waters, as they are stationary components used only while the boat is on the trailer. They also do not provide ventilation; in fact, ventilation is more relevant to keeping the hull dry or preventing mold while the boat is stored. Additionally, bunks do not enhance the boat's speed during transport; they serve the sole purpose of supporting the boat securely on the trailer.