The coxswain (or simply the cox) is the member who sits in the boat facing the bow, steers the boat, and coordinates the power and rhythm of the rowers – by communicating to the crew through a device called a cox box and speakers.
They usually sit in the stern of the boat, except in bowloaders where the coxswain lies in the bow.
Bowloader are usually seen as the coxed four and coxed pair type of boat.

It is an advantage for the coxswain to be light, as this requires less effort for the crew to propel the boat.
In many competitive events there is a minimum weight set for the coxswain to prevent unfair advantage.

International (FISA) – 55 kilograms (121.25 lb) (Men's, U23 men's, junior men's boats), 50 kilograms (110.23 lb) (Women's, U23 women's, junior women's and mixed boats)
UK (British Rowing) – 55 kilograms (121.25 lb) (Open and mixed boats), 50 kilograms (110.23 lb) (Women's boats), 45 kilograms (99.21 lb) (J15 and younger boats)
US (USRowing) – 120 pounds (54 kg) (Men's boats), 110 pounds (50 kg) (Women's boats)
If a coxswain is under the minimum weight allowance (underweight) they may have to carry weights in the boat such as sandbags.
The coxswain (or simply the cox) is the member who sits in the boat facing the bow, steers the boat, and coordinates the power and rhythm of the rowers – by communicating to the crew through a device called a cox box and speakers. They usually sit in the stern of the boat, except in bowloaders where the coxswain lies in the bow. Bowloader are usually seen as the coxed four and coxed pair type of boat.
It is an advantage for the coxswain to be light, as this requires less effort for the crew to propel the boat. In many competitive events there is a minimum weight set for the coxswain to prevent unfair advantage. 
International (FISA) – 55 kilograms (121.25 lb) (Men's, U23 men's, junior men's boats), 50 kilograms (110.23 lb) (Women's, U23 women's, junior women's and mixed boats)
UK (British Rowing) – 55 kilograms (121.25 lb) (Open and mixed boats), 50 kilograms (110.23 lb) (Women's boats), 45 kilograms (99.21 lb) (J15 and younger boats)
US (USRowing) – 120 pounds (54 kg) (Men's boats), 110 pounds (50 kg) (Women's boats)
If a coxswain is under the minimum weight allowance (underweight) they may have to carry weights in the boat such as sandbags.
Rowing (sport)