Another way to avoid the rush in the swim out is wait a minute for them to get off, and then go. I did this in my first very populated triathlon. Then by the time a minute had passed people were already dispersing in there own directions and lines and I could just swim past. I also do a lot of sight seeing while I swim, if it is clear I look at fishies and plants and garbage...If it is murky, when I breathe to each side, I look at the shore, the sky and admire the view. Same on bike and run. Really, except for the elite folks, time and placing shouldn't matter much. Good luck!