OK, what do you guys do to wax the bottom of your boats that live on a trailer? In my case it's a 15 ft fish-n-ski, empty weight somewhere around 1100 lbs.
If you're really concerned about it, there's a couple things you could do...
wax it at the ramp, put in and re-trailer it but a little farther back on the trailer so you can get to the parts that were covered before. Then put in and retrailer normally.
Second option, you could build a frame to hold a large hook that holds a belt that lifts the boat... but that's a lot more work for a wax job... save that for the paint job.
With the rig parked on a flat surface and trailer wheels blocked. Crank the tongue jack all the way down so the tongue is as low as it will go. Block the back of the boat directly under the transom, remove the tie downs and then crank up the tongue. The trailer will drop away at the stern of the boat. Go only high enough that you can get the job done. At the front of the boat you'll need to be a little more creative but a padded block of wood and a floor jack placed under the keel will raise the hull far enough to was any additional parts that can't be reached. Do the job quickly and make sure you understand that you could get your hand pinched and severely damaged if you do a rotten job of blocking and jacking. Use some common sense here.