Hi Alex,
I have an R-21 EC and here's how I load the boat onto the trailer:
I back the EZ Loader, one-axle trailer into the water until the keel roller is at water level. Then I drive the boat onto the trailer. This is usually a very easy task since the trailer's horizontal support beams guide the boat into the proper position. When there is a heavy cross-wind, I sometimes use the bow thruster to ensure the boat glides straight and true toward the winch.
I usually have someone on the dock letting me know how close I get to the winch. They hold their hands apart, and bring them closer together to approximate the distance from boat to winch. There have been many times when I single-hand this, and don't really need that on-shore assistance.
When I get within about a foot of the winch, I turn off the motor. This is always close enough that the boat is resting on the horizontal supports and won't float aimlessly away. After I turn off the motor, I go to the bow and -- with varying degrees of grace and klutziness -- step off the boat and put my right foot onto the winch (just behind the rubber roller). Then I lower my left foot onto the trailer, which is usually above the waterline. I then put both feet on the trailer for a more stable base. Then I connect the winch strap to the boat, crank it on up and attach the safety-chain connector to the boat, as well.
Note to Dave and John Livingston: I have often thought that a future design for trailers should include -- for lack of a more eloquent term -- an elevated "metal cleatish footpad" between the winch and its rubber roller to more easily enable boaters to step from the boat to the trailer. That would make it much easier to complete that boat-to-trailer hookup we all need to make.
Hope this helps, Alex,
Cheers,
John