Here's why rowing teams have one significantly smaller member sit nearly motionless in the back of the boat

On the eight-person rowing teams at the Olympics, among the tall, chiseled men and women powering the boat sits a small, seemingly motionless member in the back of the boat.

This is a cockswain, and though their job may look meaningless, they actually serve an important purpose.

Pronounced "cox-en", they are significantly smaller and lighter than the rowers because they're not powering the boat - they're steering it and directing team members all the while.

As the New York Times' Juliet Macur wrote in 2012, a coxswain "is like a coach in the boat, steering, executing race strategy, keeping a crew synchronized and motivating rowers to pull harder on their oars.

Macur added that it is a role "virtually unique in sports because that person does not contribute physically to the competition."

If it seems like an easy task, it's not that simple. As Katelin Snyder, the cockswain of the US women's eight rowing team told The Hamilton Spectator from Rio, she's not just telling the rowers to go faster.

"'Go faster' could mean pull harder with my arms or it could mean swing more with my body or step quicker with my legs. So when I want them to go faster I have to specify where and how we're going to do that together."

Of course, as directors and the "brains" of the boat, cox often try to contribute as little weight as possible. Take Sam Ojserkis of the US men's eight team. According to the US rowing team's official page, Ojserkis is listed at 5-foot-8, 122 pounds. The next smallest member of the team is Michael DiSanto, who is listed at 6-foot-1, 195 pounds.

Viewing the cox next to the massive rowers can often be a source of comedy. Here's Ojserkis next to 6-foot-8 Austin Hack:

Or 5-foot-7 Phelan Hill of Great Britain's men's eight:

Snyder is just 5-foot-4, 110 pounds.

From a distance, they look like specks next to their massive team members:

Rowing teams value the cockswain. Traditionally, after a win, the cox gets thrown in the water. Here's Snyder being tossed after a win in 2013 at the World Rowing Championships:

We'll see if any rowing team is cruel enough to throw their cox into the Rio water in these Olympics.