The swim event consists of 'waves' comprised of age-grouped athletes such as 'Men 30-34', etc. A new wave is started every 3 minutes with the first wave going off at 7:30 and the last wave at 9:20...you can see a unique view of that in the time lapse at the beginning of the video.
You'll notice a lot of aerial footage in this video. You can see more of my projects at FeatherCloudProductions.com