How do I get this see through water effect?

[William22842306alge]

I want to composite a product into a landscape by the beach with parts of the product being swept by water just like the image attached. Any idea on how I do that or know of a good tutorial showcasing similar results?

Thank you! 

[Myra Ferguson]

You could try Generative Fill to add the waves over the bill of the cap.

Alternatively, you could try using a Layer Mask on the bill so that only a slight transparent portion of it shows through the waves. It might also help to copy/paste that section of the bill and apply a blend mode to it to make the color of the bill more apparent. You can tone it down by adjusting the Opacity in the Layers panel.