Why is the Coxswain always so small in rowing?

Question

Every race I've seen, the coxswain looks like a tiny person, and everyone else in the crew is at least a foot taller and like 50 lbs heavier. Why is this?

Answer 1

To put a different aspect on the previous answer:  who would you rather drag around in the boat, David Spade or Chris Farley?  

:)  

Answer 2

First and foremost, the Cox isn't adding any power to the craft. They are extra weight to carry. You may have noticed that crews even dump out their water bottles just prior to the start. Every ounce can count.

Secondly...you're looking at that Cox standing beside their team mates. Those guys are big.