I used to have no trouble closing the gap by setting my electric over hydraulic trailer brakes at their highest setting, getting the trailer going in the ramp parking lot, then slamming on the brakes. There was no more stress from this than average SF Bay Area traffic. Then, I re carpeted the bunks and put a softer bottom paint on and couldn't get it to work. Liquid rollers did little for me because the fuzzy bunk carpet just soaked it up. Then I figured out how to solve the problem. The boat will rest fine on the trailer just six inches back from the stop (be sure to hook up the strap and the safety chain, tho). It makes the tongue light, but that's ok for a short drive. Living in a hilly area, I just found a nice, moderately steep incline, headed down it and put on the brakes hard at the bottom. Problem solved and the boat is in its proper place.
Launching with this fuzzy bunk carpet takes more oomph driving the boat off, too. Next time, smooth bunk carpet.