Those who have a problem getting the boat far enough up the trailer- are you loading onto dry bunks?
Some boat launches were designed by imbicils who don't know anything about boats that weigh more than a Jon boat with a 5HP outboard. They're usually too short and at the wrong angle to load without driving the two vehicle into the water. What they should do is make it a few feet longer, more steep at the waterline and reduce the angle as it goes farther in, so the trailer is more level.
The first time I had to load a boat at Lauderdale Lake, it was before they rebuilt the ramp and as I backed in, I watched the guide posts completely disappear- the ramp had been washed away by all of the idiots in their bass boats with 150HP motors.