So far this year, as of today, I have spent more than 135 hours in the pool. That is up from 113 last year - when I was doing Ironman. It's actually only an average of 2.5 hours a week all year... so it doesn't really seem like that much. But the increased swim volume - and yes, I know it's more about what you DO with your time, rather than the amount of time in general - really got me back to the swimmer I used to be many years ago.
Noa writes amazing swim workouts and I got a couple of strong lessons from them. One is the ability to do constant variation in speed. She has a lot of main sets that will throw in some "fast" work in the middle of long tempo or steady sets. I figured out the point of that during my swim in the Leadman 125... whenever I was falling off the feet I was drafting off, it wasn't a big deal to sprint back up to catch them again.
The other lesson was if you swim hard in training, it's not that hard to race. I know, you're thinking: "DUH!" But... with every tri I did this year, I'd finish the swim and my heart rate would recover almost immediately, allowing me to push the pace early on during the bike. It used to take me awhile to settle into riding; I'd totally be red-lining starting the bike, gasping for breath with my heart rate sky rocketing. This year with the increased swim volume and (probably more importantly) the increased intensity, when I exited T1 I was ready to push the pedals without needing to recover from the swim.
I am hungry to improve in 2014, so look for me at the pool even more and working even harder!