You don’t need to buy anything for your boat to back down steep ramps. Your boat already comes with this “accessory.”
There’s one ramp in particular that I launch at on occasion that puts the driver in the same scenario. The ramp is incredibly steep and you have to work the trailer through a turn as you back down the ramp. Once the trailer goes “over the edge” and down the ramp there’s no way to see what the trailer’s doing until the truck itself starts down the ramp. By the time the truck starts down the ramp and the boat again becomes visible… if you were off a little at the top now things are WAY out of whack and you need to start over.
Unless you put the light pole for the nav light in the socket at the rear of the boat.
Most light poles are more than tall enough to be seen in either the rear view or side mirrors making it easy to track the progress of the boat as it is backed down the ramp. At night this little aid is particularly effective if you turn on the running lights. It is hard to misplace a glowing orb on a 4′ pole sitting on top of the rear of your rig.
Every boat has one which makes it handy. And it only takes seconds to install / remove which makes it a perfect solution for those rare launches at a steep ramp.