idea is good -- patch of sand in front is showing a bit too much of cloning -- shadows could use some softening -- maybe some spread as they have too hard and edge also they seem a bit too much on top of the sand try a different blending mode maybe overlay with another layer in multiple with a lower opacity

Thanks Alan I did some touch up any better ?

And Thanks Giulia I took care of that I don't know how I missed that

cute little guys...the top of their submarine needs a bit of adjusting, though... the cut is too straight, maybe try to make it more round?