I finished the pieces for this tank awhile ago, but I needed to learn crochet in order to finish the neck edge and armholes. I found a terrific tutorial on YouTube. Very Pink Knits showed me everything I needed to know to learn to crochet and work the shell stitch. Yay!
It looks like a cable, but the effect is created by moving increases and decreases. Worked from a pattern called Evening Breeze in Knitter's magazine, 2004.