I noticed one of the cleats on our boat was loose, and tightening the screws didn't help (they just spun around loose). After taking the cleat off, we found that several of the brass screws had broken off at some point in time, which probably loosened the cleat and let water in (which in turn rotted the wood). That explained why there was a leak in the forward stateroom just below the cleat.
What we found after taking the cleat out...
After clearing out the rotted pieces of wood...
After adding some reinforcement...
After finishing with filler, with the cleat shinned up and ready to go back in...
Jim Geier
Cheoy Lee Trawler 55