You are the weakest link
One of the shorter term boatyard projects I actually enjoyed. I noticed this rusted out connecting link the past few seasons and decided it was time to do something about it.
This is only a three step process;
1. Cut link in half with angle grinder (now my favorite powertool)
2. Slam the new link with a hammer to deform 4 retaining pins.
3. Stop as needed to apply bandaids to fingers
Note the damaged corner of the cement block where I was holding the link. I only hit my hand twice out of about 400 swings.