I keep wetsuit boots and a pair of chest waders available to help get boats on trailers in difficult launch ramps when either the wind, waves, or bottom conditions make centering and settling down the boat difficult.
I even put a drysuit on one time to retrieve the Sea Ray during the winter, and the new trailer didn't have guide-ons, yet.
There are definitely times when three people, two of them pretty strong and in the water, are needed to get a large boat on the trailer and up the ramp if you don't have a dock alongside.
I power boats onto trailers when I can, but often a little excursion into the water is more precise and less likely to get yourself and the boat and/or trailer into trouble.
And when it's 100-110 or more degrees, I'll even volunteer to be the first in the drink!
After some small boat sailing regattas, when the dock and ramp were very busy and required a long wait, we'd leave the trailer on the beach, down rig the boat off shore, and then jump overboard and swim the boat into the beach to the trailer with the painter (bow line) in our teeth doing a backstroke. Felt good after a long day on the water.
Joe. :teeth :thup