photoshop collage

I plan on visually diving into the ocean, descending deeper with each collage. Beginning at the surface and ending at the darker depths, the general color scheme will become a darker shade of blue with each collage (as denoted in diagram). Having never dived into the ocean, nor have much experience with marine biology - the imagery shall become more ambiguous and surreal with each descent.

As for a sign or symbol - I leave it to the viewer for their own interpretation as they journey through the darkness.