I was on a work trip for a conference in North Austin, when I came upon a real jewel of a swimming location - Pure Austin Fitness at Quarry Lake.
This is a health club that owns a water-filled quarry immediately behind it, with a running trail that circles the lake as well.
The lake is jade green, reasonably clear, and has buoys at the perimeter so you can practice siting. Austin is crazy about triathlon and outdoor fitness, so this lake is done right. Here is a map of the buoys and lap distances.
I showed up and paid the $21 plus tax to get a guest pass. They slapped a bracelet on me and told me to have fun - the lake closes at sunset. I asked if I needed a wetsuit and they said not at all. The water is currently 82 degrees.
I walked down the trail, hopped in, and started cranking out laps. I alternated swimming clockwise and counterclockwise for five laps, timing myself on each one. I got out on the dock between each lap and took a sip of fuel, and hopped back in. After the first lap (that I considered a warm up), I got the bright idea to try different freestyle techniques to see which was fastest.
The slowest was swimming freestyle that felt firm but relaxed. That gave me a time of 13:23. The second fastest was "Sun Yang Style", which has my head buried and trying to swim "downhill" (12:43). The fastest? That's I style that I'll call "Narrow Arrow", where I tried to keep a narrow and rigid profile, focused on entering the hands directly ahead, and pulled with a forearm catch that closely paralleled my trunk in angle and didn't get far from my body (12:27). One thing that I noticed about swimming that way - It seems like it both reduces drag and gives you a higher stroke count. I don't know of any videos showing this technique, but I remember that Rich Roll swims this way and he is fast.
Leaving the lake, I was extremely pleased with the experience. I could tell that my sighting and swimming in a straight line ability had improved dramatically in just an hour. The lap format allowed me to compare and find the best stroke technique. It was windy up above the lake while down at the water level, it was sheltered and as smooth as glass. Another perk that lots of pool swimmers might enjoy was that there is plenty of room. No fighting for lanes! I loved it.
If you are visiting Austin, this experience is definitely worth the $22. If you live in the area, strongly consider making this a regular place to hit the water. Your open water abilities will improve tremendously. Just bring a wetsuit for the colder months.