I've had years of practice. If I can see the trailer in my mirrors, I can back it in. When I move a trailer with my Razor, I can't ever see it right and can't back it anywhere.
I used to be a roofer. The boss had a large generator/welder on a small Harbor Frt type trailer with a tongue shorter than mine. It was too narrow to see in the mirrors and with that short tongue, it was impossible to back. By the time it came around enough to see in a mirror, you'd already lost it. It was easier to just get a couple guys to move it by hand. Boat trailers usually have long tongues are are very easy to back as long as you can see them in the mirrors.
