Trinkka, the two photos of your friends set up is perfect without the additional front roller and jack set up. The other roller further back and the adjustable winch post setup is all he needs.
Now, to recover a sailboat on a trailer with bunks the boat must be floated onto the trailer, you can not winch it up out of the water like a power boat! If you must do that then change your bunks over to rollers. A power boat has straight sides, bottom, and trailer bunks, your sailboat is curved all over the sides, bottom, and the bunks are also curved, something has to give.
You must submerge your trailer so the front edge of the bunks are 2 to 3 inches below the surface of the water. In this position the boat and keel is floating above the bunks when floated onto the trailer. The boat stops moving forward because the hull is now stopped on the front edge of the bunks which are only inches below the water, if you make the bunks deeper then the boat will move further forward but the stern will be floating higher above the trailer and harder to control. Your friend’s dry working platform pictured on top of the brake unit will have to be raised about 6 to 8 inches to keep his feet dry. That platform where it is now tells me he is not getting his trailer deep enough in the water!
The other bow roller on the trailer is mounted on an adjustable bracket, that roller needs to be moved up to about 1/2 inch below the bottom of the hull. You keep this roller lower than the hull to allow the trailer to flex a little going down the highway. Pulling over uneven payment at high speeds will cause your trailer to flex, if the roller is up tight a lot of the forward hull weight will be carried by just this roller and not the bunks during this bend in the trailer.
Your buddy had to drop this roller down out of the way because with the trailer not very deep in the water the front of the bow was hitting this roller and he could not get it up over the top of it.
This roller up near the hull and the front of the bunks submerged (the trailer is deeper in the water) the bow will now float higher and roll up on top of this roller. You’re now going to lift the bottom of the hull above the front of the submerged bunks and the keel is no longer hitting its bunk With a line attached to the bow you should be able to pull the hull forward 12 to 18 inches. As this roller lifts the bow out of the water the stern sinks thus starting to match the angle of the submerged trailer.
At this point the bow eye should be 12 to 18 inches from its final resting place. The winch level or higher can now continue to lift the bow up and sink the stern, the trailer roller will carry most of this weight which isn't much because your only lifting the bow a couple more inches and the stern is still floating, maybe only about 100 to 200 pounds of pull on the bow eye and the winch.
Your buddy is doing the same thing with the forward roller and jack, lifting the front of the hull and keel above the front of the bunks so the winch can pull the boat forward, but because he is not deep enough in the water he’s probably pulling up to 1000 pounds up and out of the water, that's why you can buy a super heavy duty bow eye retro fit for your boat.
Your buddy’s trailer has a tongue extension, bow roller and an adjustable winch set up, and he still gets wet!!!!!
