Lovely work, great ideas!!!! I do not have an “underwater” shot. But my granddaughter was little mermaid for Halloween. I tried to make it look like she was sleeping underwater water added a blue layer, above the picture, with a low opacity to give the picture a blue tinge. I used Cass mask maker to create a mask for her body. I had some Little Mermaid clip art. I used a water paper and added some sand on the bottom with a few bubbles. I followed Cass text to path on an oval around Lexi. Added drop shadows per Cass’s guide. I set them up as defaults what a time saver. Overall I was pleased I think I got the effects I was looking for.