reminds of of the numerous times every day that someone will load their trailer, whether it be a tractor, lawn mower, car, truck, boat, whatever...and not put a tie down one on it. I follwed a guy once almost 40 miles, had a commerical lawn mower on his trailer, rear tires hanging off of the trailer and the whole mower just about ready to fall off. I tried my best to stop him an finally gave up trying. It finally came off. Totally destroyed it. $15,000 lawn mower and $20 worth of tie downs would have saved it.
Then there's those who'll just throw a strap across the front of it and call it good. Better than nothing. But just as important as tying down the front, is tying down the rear. Think about it. In a panic stop, with nothing holding the rear, it will try to go forwards. I've seen a flat bottom impaled into the back window of a Toyota pickup, no rear tie downs, driver had to stop quick to avoid a car in front of him. Boat broke the front tie down and went right up over the bow roller and into the back of the truck. Guy was lucky to be alive.
And then on your bow roller. The boat's bow eye goes under the bottom of the roller, run the strap and hook under the roller to the eye. This way in a panic stop, it's not as likely to ride up and over. And it won't if it's tied down in the back like it should be.