Missing?
Hi, Those blocks are used for centering and for the pivot that holds up the keel. Correctly placed, the blocks should look like flat plates that are flush with the bottom of the hull. You need to replace this Stainless Steel bolt. I would go to Catalina Direct which can be found online and get replacement bolts as well as an Owner's Handbook for your boat. The handbook includes much info.With the replacement bolts comes a small amount of Loc-Tite to prevent the bolts from working out. I hope that the bolt isn't sheared off. That could come from someone over tightening the bolt. A sheared off bolt would make the repair more difficult. At any rate, you need to replace this bolt.