Regarding replacing centerboard line without a lift.
I have a 93 Hunter 23.5 that I bought last year, moved up from a Catalina 22 and a Compac16.
The boat sat in a lake for 20 years in Texas. I fixed the big splits in the rudder last year and
I have been reading a lot of posts on here about how to replace the centerboard line, and forgive me if I missed some posts but I did not read about the technique I used.
Since the CB has been drying all winter I did the removal at home, but to put it back on I went to a gentle slope boat ramp, floated the boat, then on the empty trailer added five 12' long 2x6s to each bunk, cutting them in half to account for the curve of the bunk. Using lag bolts and countersink to have the five as one unit., then lagging up underneath the original bunk, and using one inch wide 15 feet long straps to lash them and some old blankets and tshirts on top as a cushion, put trailer back in water, pull boat out, had room to attach repaired CB and new line, float boat again, remove extra bunk boards.
because I needed to repair huge split in edges of CB I did not want to get water inside. I also did not want to jack hull in spots and risk damage. So I removed all weight, rudder anchor, everything inside. I keep the boat in a 22'x30' enclosed carport with 8' sides and 12' at the peak. Rather than removing mast, I left stays attached and lashed the mast up under center frame of carport to remove that weight.
Rather than jacking the boat in spots. I usually have a 5 inch drop hitch, so I put on a 4 inch riser hitch to raise tongue. and hooked up to pickup, then using two floor jacks with the handles facing toward bow. I jacked the trailer axles 9 inches. Then I blocked boat up in 8 places, using cinder blocks, topped with foot square plank, and plywood to shim, and old tshirts to cushion. Two stacks just forward of bunks and just off center line with enough gap to slide CB forward inbetween. the two stacks right behind axles and farther from center line outside of bunks, and the other 4 stacks aft of that. Then I lowered trailer axle, and hooked up drop hitch to lower tongue.
To be extra safe I added the five extra 2x6 bunk boards on each side, lag screwed and lashed, with padding. If the boat falls, the trailer will protect me.
I removed the CB, removed the extra bunk boards, put on riser hitch to raise tongue, then jacked trailer axle to have trailer take the boat weight, removed cinder blocks, and then lower.
If I would have just been replacing the line and not fiberglassing, I would have removed CB at boat ramp after adding extra bunk boards.