In this video I demonstrate the fisherman’s rib stitch in slow motion.

You can see my entire slow-motion playlist here.
My Fisherman’s Rib Hat and Scarf tutorial is here.
Proactive lifelines

Instructions for working Fisherman’s Rib:
Cast-on a multiple of 2 stitches, plus 3
Setup Row (RS): K across all stitches
Row 1 (WS): *P 1, K 1 into stitch below*, repeat between *s to last stitch, P 1
Row 2: K1, *K1, K 1 into stitch below*, repeat between *s to last 2 stitches, K 2
Repeat Rows 1 and 2 to desired length, BO on WS, while working Row 1

Instructions for working this stitch in-the-round:
Cast-on an even number of stitches, and join to begin working in-the-round.
Setup Round: K around all stitches
Round 1: *K1, K 1 into stitch below*, repeat between *s to end
Round 2: *P 1 into stitch below, K1*, repeat between *s to end
Repeat Rounds 1 and 2 to desired length, BO while working Round 1
To purl into stitch below, approach the V below the current stitch from back to front.