This is my favorite stitch when I have an area of water to stitch.  It not only gives movement, but the addition of a metallic in Step 2 looks like the light reflecting off the ripples in the water. Normally I use two plies of a Needle Necessities Overdyed Floss to work Step 1 and a #4 metallic braid for the tent stitches in Step 2. If you're working over a painted canvas, try using a pearl #12 in a solid color close to the main color of the water. The pearl #12 will allow the painted canvas to shadow through, eliminating the need to do the extensive shading normally found in a painted canvas. Then try two strands of white Accentuate for the tent stitches in Step 2.