The centerboard floats
We had the same problem with our H23. The centerboard floats, and you are fighting against that when trying to pull it down. I drilled some 1" holes in the bottom and filled it with lead shot and epoxy. I measured out the lead by floating it flat in the bathtub, holding the pivoting side underwater, and adding weight to the other end until it barely started to sink.I also smeared trailer axle grease on the areas where it scuffs off the anti-fouling paint where the centerboard rubs against the iron. That keeps the barnacles from growning on it and jamming it.I used a light duty 4:1 block and tackle to pull down, and just a line to pull it up. It still takes some muscle. If I hit something, I want it to break the block and tackle in an area that I can fix easily.