It takes a total of 4 months of classes to go from being terrified in water to becoming a masters swimmer. Not that anyone has ever been ready to learn that much that fast!
The steps are all written down and if you follow them at your own pace, it’s inevitable that you’ll become a Masters Swimmer. In reality, it usually takes 1-2 years for people to schedule all these classes, fund them, and rearrange their minds: yes, even they, who felt they were at the bottom of the swimming totem pole for their entire lives, can be a regular masters fitness swimmer.