What is the backing plate behind the crack ? I see nuts,I think???
If it is not getting any larger on either tack then I would most likely just relax the rigging and do some glass work and then tighten it back up.I assume it is a 20' foot boat and it should not take much time to clean that out and rework the tab.Then you will be on your way sailing once again.Just be neat and tape everything off and put plastic everywhere as to catch the mess.
As said before the spray reminds me of the ceiling texture used in houses.