ch 11, sl st in second ch from hook, sl st to end, ch 1 turn. (10 sc)

sl st blo to last stitch, ch 1, turn.

repeat until 32 rows, 16 ridges, ending with hook opposite side to starting yarn.

ss tog (leaving seam to sew up later)

1 sc in first ridge, 2 sc in next ridge, all the way round (24 stitches)