Large vertical cracks along underside of board

[dikmorf]

I recently bought this mid length board and after a few sessions noticed a bunch of cracking on the bottom. Could anybody suggest whether these are something I should worry about?

[jaffa1949]

Stress fractures at some time the board has been pressure under a wave and flexed heavily and those are the flex lines.
If they happened while you were using you may recall how it may have been caused!

Remedy, not much, a reglass but you will have heavier board, they will eventually absorb water into the foam , heavier board.
Depending on your economics, it is ride till it dies board!

[waikikikichan]

I recently bought this mid length board and after a few sessions noticed a bunch of cracking on the bottom.

1) Did you recently buy it NEW or USED ?

2) Can you show a picture of the rear of the board. The area of the fins that for some reason is black.