You need a surveyor to give you a better picture of what you''re looking at. Among other things s/he will do percussion testing and check moisture levels where ever the deck/sole....has been penetrated buy a fitting or hardware of some sort.
If you have simple glass-core delamination & the area measures dry on a moisture meter then the fix is very easy, just inject it with
epoxy (see Don Casey''s or Alan Vaitses books on boat repair). If the core is wet, then that''s another issue although certainly not a kiss of death and well within most people''s ability...as long as they have basic to moderate shop/tool talents.