Looks cool and easy enough, rowing while in a plank. I wish that were so. 

After seeing enough people butcher the movement, I've decided to do a breakdown of how to perform it. 

Equipement needed: 

Sled, Battle Rope, Airex pad (optional)

1. After you tie the rope to the sled, pull the rope out until the end and place an aired pad right in front of it. 
2. Get into a 3 point plank, and without allowing the hips to rotate, row the rope and pull the sled towards you. 
3. I'm shown here with a cone to really hammer down the point of not allowing the hips to rotate.
4. To make this move harder, feel free to bring your legs closer together to make yourself "less stable" and thus forcing you to work harder and stabilize.