Underwater Dance Effects

Merge down the girl's layer and the tail's layer: Layer – Merge Down (ctrl+e). Make a copy of this layer (ctrl+j) and blur out the copy, using the Filter – Blur – Gaussian Blur.



Change the layer's type on Overlay and combine after that the layers.



Make the corrections on this layer's colors: Image – Adjustments – Selective Color.



Copy this layer and situate the copy lower than the main girl's layer and blur it out on its vertical direction, applying the filter shown here: Filter – Blur – Motion Blur.



Then mark out and delete that part of the layer that gets outside the lowest girl's contour.



Minimize the layer's Opacity till 60%.