Centreboard Bumps

I’m new here so be nice…..

I have just bought a Laser all good but one thing is the centreboard has a few bumps (see photos).

Previous owner things it happened when he left the board out in the ( Australian) sun.

Not sure what board construction is (boat is from about 2012).

How can I repair? Is it okay to sand down, then recoat (with what)?

Thanks