My son coxed his first boat at the age of 11 and made quite a good job of it. He was in the junior squad at the club and was learning to scull so he had a working knowledge of the rules of the river and had been coached on the basics of coxing.
I mention this because coxing can be a useful role for junior rowers in terms of their understanding of rowing, their usefulness to their club and their development as responsible people. That said, coxing is not for everyone and I have known adult rowers who (even if they were the right size) I would not want coxing my boat.
The bottom line is that the cox is a very important person in any boat. Technically the cox ‘owns’ the boat, outranking even the coach. The cox is ultimately responsible for the safety of the crew and other river users and can overrule any other instruction in safeguarding his or her crew. The cox’s responsibility for the boat and its occupants begins when he or she calls ‘Hands on!’ to get the boat from its rack and doesn’t end until the boat is safely on its rack again at the end of the outing.
A good cox can raise a crew’s performance to levels they would not otherwise achieve and a poor cox can make a competent crew look incompetent. Ideally a cox will have learned to row or scull and will know enough key coaching points to help the crew sort out any issues caused by poor rowing technique during the outing. They will act as the coach’s partner in the boat and a key communicator between the crew and coach.
Needless to say, a good crew will treasure their cox, thank them at the end of every outing and keep in mind that without them, the outing might not happen at all.