I think !
Leon is right.I would be doing this from on land on the trailer, lift or hull support jacks.I also believe he is correct about the waterline areaas it relates to the "Radiator hose". After looking at my 22' Catalina 2000 Mark II there is no way I could remove that hose without sinking the boat. Unless someone out there has a very big manhole pump they want to lend me!!! LOLIf in a real bind it could be done while in the water but it will take more than one person.In reality, I would create or borrow a sling to remove the boat from the water.Have it hoisted out, and blocked up while the repair is done, since the keel is swinging feely with no control to it.Orif possible swedge or nicopress a fresh piece of cable onto what remains of the cable that is still attached to the keel feed it up thru the hole and into the hull and cut and swedge or nicopress the new piece onto the good existing old piece still attached to the drum. Then slowly raise the keel enough to load it onto your trailer and do the replacement then.I agree with some of the others when they say preventitve maint. is the key to a sound swing keel. Take the time to check the pivot point, hanger, bushings and bolts.One final thought. Make sure that the nicopress or swedge fittings can take a load of the full weight of the keel. Be it 500lbs or 1000.Happy Sailing Dave LaPere