When launching your boat, what should you disconnect before backing down the ramp?

The correct choice is to disconnect the trailer winch line before backing down the ramp. The trailer winch line is used to secure the boat to the trailer. By disconnecting the winch line, you ensure that the boat can smoothly slide off the trailer into the water when you back down the ramp. This helps prevent the boat from becoming stuck or causing damage, as well as ensuring it can be safely launched.

Meanwhile, the other options are not relevant in this context. Trailer lights typically do not need to be disconnected and often remain connected while launching, as they are important for visibility and safety on the road. Safety chains should remain connected until you are ready to separate the trailer from the towing vehicle at the ramp, providing an additional layer of security. The engine does not need to be disconnected either; in fact, you should keep it in working order for when you actually launch the boat and need to start it in the water.