Step-by-Step
Stamp Urchins LAV631 with Versafine Clair Medieval Blue, Marine Kelp LAV625 with Versafine Clair Rain Forest and Willow LAV173 with Versafine Clair Shady Lane.
Use a Hill Mask to create some rocks, hills, and ocean floor with Elements Ink Graphite.
I stamped some with first generation and some with the fainter second generation stamp to create the illusion of some being further away.
Using Elements Ink Blue Atoll, add colour to the mermaids and fill in the white centre with some lovely blue!