Peter Vu's Ironman Blog - Vineman 7/31/10

Here's an article discussing some efficient techniques for open water swimming:

Next time you are in an open-water event, don’t forget these critical steps for fast and efficient sighting: Arch your back, kick harder, lift only your eyes out of the water, breathe to the side and sight only as necessary, but as often as necessary. With practice and implementation on race day, you might find that your new best time is due to swimming a more direct route around the buoy.

Read more here.