I used the Lawn Fawn set Mermaid for you and I stamped it with My Favorite things hybrid black ink onto Schut watercolor paper.
I made a mask of the sitting mermaid with Inkadinkado masking paper.
I used a Spellbinders scalloped circle die to make a window in a cardpanel and stamped the sentiment on the panel too.
To watercolor my scene I used Distress inks and Winsor & Newton Iridescerent medium for a glorious shine.
The medium makes the Distress inks a little streaky, but I think that works well with the see background really, adds depth and interest.
I accidentally colored her tummy blue as well, tried to wash it out with clean water, but ended up giving here a purple belt ;-).
I realised too late it was a two piece suit ;-).
Mounted the cardpanel with foamtape and adhered the scene onto the foamtape, then applied tape runner to adhere it to the cardbase.
For more information on the Simon Says Stamp Monday challenge, see this