Great drill if you train on an RP3 or other rowing machine where the seat and feet both move relative to the trunk.
Goal of this drill is to develop body control.
The more trunk(spine) control you have the less the seat will move towards the stern (towards feet) at the finish.
Seat control comes from the strength, power, and ability to stabilize the trunk (spine) throughout the rowing stroke.
Weakness is shown when the seat slips into the stern at the finish.
Spine slumping (C-shaped spine)
is a weaker body position and it shows up as the seat drives into the stern at the finish (boat check).
Spine control (as close to anatomical spine position as you have strength to handle).
Try this drill and check out your trunk control.
Anyone can build this skill once you understand how column core activation works and you begin building it. I will give you a hint: traditional weight training and planking don’t teach this skill.