What are surge brakes designed to do?

Surge brakes are designed to activate automatically when the towing vehicle slows down or comes to a stop. This system uses the inertia of the trailer to engage the brakes, providing a smoother and more controlled stop. As the towing vehicle slows, the trailer pushes forward against the surge brake actuator, which then compresses and activates the brake system on the trailer. This function is particularly beneficial for ensuring both safety and stability while towing, especially when managing sudden stops or deceleration.

The other options do not accurately describe the function of surge brakes. For instance, they do not engage when a boat enters the water or require manual engagement by the driver. Additionally, while surge brakes do contribute to stability by preventing excessive forward momentum, they are not specifically designed to prevent swaying; that function is typically managed by other means, such as load distribution or sway control systems.