After spending the last 40+ years fishing on the gulf coast with my dad we have seen the best and the worst of people launch boats and PWC's.
My dad and I have spent some late mornings and afternoons watching the action, I have seen a few boats left dry on the ramp without the trailer, one day my friend had just replaced his rollers with the slick pads and when he backed up to the ramp, the boat came off the trailer about 25 feet short, to say the lest the hull had a case of ramp rash.
Usually most of the time it's just fun watching newbies just trying to back a trailer straight down a ramp, or trying to get the boat back onto the trailer after a day of boating, remeber, boats have no brakes.
Of couse I myself am flawless in my trailering abilities.
Allen