I agree 100% with Jays comments those scars are way to deep, size wise they are fine but change the bump depth (i think thats what ur using).

On the water side, gnomon had a great tutorial on underwater lighting effect for a dolphin scene.

You can find it here:

https://www.thegnomonworkshop.com/tut.../lightfog.html

https://www.thegnomonworkshop.com/tut...imple_fog.html

Both cover fog and should give you a little insight on how to get that underwater feeling.

Its a tough one to get 100% right, it took Pixar months to get it right in Finding Nemo and they still hate it :p