This was commissioned and I used Caron Simply Soft in two shades of blue and white and did a basic crochet shell stitch throughout.  The border is one round of single crochet in blue, then double crochet in white, then a picot for the border.  There are 17 shells across and then 11 rows of the blue colors which are 4 shells wide (can you tell i made up the pattern?) 🙂