I was a competitive swimmer in H.S... and graduated in 1991. After that I swam off/on after that. Joined Masters swimming, etc.
I started doing tri's in 2005... and I use to train at least once a week for the swim portion on the sprints. I would come out in the top 4 of my age group... and typically 2nd out of the water.
This year... for my last tri... I basically trained around uuummm... 6 times in 2-3 months for the swim... and here were my results:
Swim:
10:03/500 yards/2 minute 01 second per 100 yards
Age Group: 4/24
Times that beat mine:
7:23
9:25
9:37
And this was a championship race.
Moral of the story... if you are a fast, strong swimmer... you will be the girls and most of the guys out of the water. Most triathletes can's swim worth a darn.
BUT... a tri isn't won on the swim... you have to be a FAST cyclist and runner to place.
I went from 4th on the swim...dropped to 14th on the bike (and I kept a 18 mph average)... and then went to 21/24 with the run (ran a 11 minute mile).
Good luck!
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather, to skid in broadside thoroughly used-up, totally worn out, and loudly proclaiming: WOW WHAT A RIDE!!!!"