Lubricating Bunks - Closing the Gap
Keep in mind that when you spray the bunks with a lubricant to make the boat easier to slip forward with the winch, the same lubricant can cause your boat to slide off the bunks sideways also if you get into an emergency situation...tight curve, maneuver to avoid something, trailer tire runs off the road or hits a rough spot.
On our Catalina 22, we were able to eliminate most of the gap betwen the bow and bow roller/stop by bringing the boat on the trailer to the stop with winch, moving the vehicle a a foot or so up the ramp....boat bow begins to swing away from the bow stop as described in the other posts, stop, winch the boat again until it reaches the bow stop. Move the truck and trailer another foot and repeat the process. Do this 3-4 times.....it drives the power boaters who are waiting nuts, however. By doing this, the most of the boat's weight is supported by the water, not the trailer bunks. Watch carefully as to what is happening between the boat hull and front of the bunks because you are putting lots of stress there. Finish the job with the MacGregor bump mentioned before, or if this doesn't work, place a rubber spacer block between the bow stop and the bow eye, and tighten winch to close the gap to trap and hold the spacer. A rubber V shaped trailer stop from the nearest boat supply house will do the job.