Hi guys,
I am wondering if anyone here knows a bit about the fin box construction of the Airush Sector V1.5.
I bought this board a while back second hand, it was hardly used. Not long after that I noticed some hairline cracks around some of the fin boxes (never hit anything!).

I tightened the fins and smeared some sikaflex around the fin boxes to prevent water ingress.
Now, that I have been riding this board quite a bit the cracks have become worse.

Does anybody know how the fin box area is constructed? Will the board take on water through these cracks? Any hints on how to improve the situation?
Thanks a lot!
Sidenote: Interestingly there is very little info on the Sector 5 out there, anybody ridden it?