Fin box cracks

[JD111]

Hi All,

I am after some advice regarding a number of cracks in the fin box of my 2006 S-Type 126 (pics attached). There are about 7-8 hairline cracks in various places (in the fin box) which generally run from the bolt holes. Two of the cracks run up the front and back (one at the front and one at the back) of the fin box and both run about 3mm onto the hull. Another two cracks run the full distance between the bolt holes. It is hard to gauge how deep the cracks are, but they are not scratches...

Should I be concerned about these cracks? Do they need to be fixed? Is this a common problem?.. Any advice would be greatly appreciated.

Thank you