Final answer:
The green stage swim benchmark does not have a set minimum distance for 1-2-3 breathing; it varies by program and encompasses multiple competencies.
Step-by-step explanation:
To achieve the green stage swim benchmark, it is not enough to specify a minimum distance for the 1-2-3 breathing technique. The green stage benchmark often refers to a level of swimming competency that includes a variety of skills such as breathing techniques, swimming different strokes, and water safety. The 1-2-3 breathing pattern, which is where a swimmer breathes every three strokes, alternating the side they breathe on, is usually practiced over different distances depending on the swimmer's age, skill level, and objectives of the training session. This drill helps in building lung capacity and improving stroke balance. To meet a green stage benchmark, swimmers might be required to show proficiency over longer distances, but specific requirements vary between different swimming programs and level assessment criteria.