What’s an example of novice coxes saying unnecessary things that aren’t helpful to the boat? The only thing I can think of is repeatedly “you got this, you got this come on!”
Basically anything that doesn’t tell them the strategy, their location, their position relative to other boats, what their rowing looks like, etc., it’s more than likely not helpful. If you listen to the recordings I’ve posted you’ll get an idea of what’s helpful and what isn’t. Sometimes it’s not even what they’re saying either, it’s how they’re saying it. Projecting an assertive, confident tone goes a long way in making sure your calls are effective and helpful to the crew.
Some super basic examples include stuff like “Come on guys, we’re almost there!”, “let it run” instead of “weigh enough” (they’re not interchangeable!), “I know it hurts!”, “Pull harder!”, and counting out (in a monotonous tone of voice) every stroke of a power 20 in sequence (15, 16, 17, etc.).
The easy way to avoid saying unnecessary stuff, besides becoming more knowledgable about the stroke and sport, is to just talk to your crew. What they find helpful or unhelpful may be different than what you perceive to be helpful or unhelpful so it’s good to get feedback from them when you try out new calls.