I've googled things like "speed of swimming progress" and so on, and I've found out how swimming has advanced in the past 100 years, all about endurance tests for accomplished swimmers, development of various swimming strokes, even swimming-pool etiquette and suchlike. It's not really what I'm after, though.
The character in question is a very fit person, goes to the gym at least three times a week, and has no problems with stamina or what-have-you. He did, however, have an incident when he was a child where he fell out of a kayak and got tangled up in water-weeds, almost drowning as a result. This means he's incredibly nervous when it comes to swimming and not very confident about it at all, especially if there are other people near him in the pool. In fact, it's pretty much a phobia.
He does have vast amounts of Stubborn, however, and has promised himself that he will learn to swim, and when he can swim 200m and not feel knackered, he can get a tattoo that he's been after for a while.
I've been told that once he gets the actual "mechanics" of swimming worked out, it shouldn't take too long for him to build up the actual lengths he can swim since, as has been said before, he's already very fit. I'm not a swimmer, however, so I don't know what the timeline would be for this.
Can anyone help me work out how long "not too long" would be? Thank you very much in advance. :D