Best way to approach cutting this out

[Arvid5]

Cut a guideline around the diver, but I still have this aqua blue layer around him to get rid of, any ideas on how to get rid of it?

Already tried colour range and sampling the outer colour, but theres specs of the same shade on the diver himself. New to photoshop by the way, would greatly appreciate the help!

 

[IamSam]

Hello.

Take a look at Refine edge...........or select and mask. Also, Matting Options.

 

[Arvid5]

Hello.

Take a look at Refine edge...........or select and mask.

Will do, Appreciated.

 

[Eggy]

Actually the lighter blue part, after the cut out, could be dealed with as if it were a halo and here's how to get rid of a halo when doing a cut out:
How to Remove Halos from Cut Outs in Photoshop