Whilst out sailing today i noticed my board was a bit soft under foot just in front of the back foot pad.

I'm not certain but think it may be due to the board being in the sun on the back of the ute. I had the plug left in as i always do. The board was in a reflextive bag.
Is this a big problem? can the board be repaired and how?? Really would like to repair it as it's not that old.
Any advise will be greatly appreciated.