I haven't touched my $600 Canon HF10 since I got an iPhone 5. The "5" version of iPhone takes excellent video. It doesn't zoom or have remote record/pause but you don't really need those features for static pool video. The audio quality (mic) is very good also, although again it's not that important in a pool video.
Here's an example: http://www.youtube.com/watch?v=ydYr6mKyVQM Remember, this is youtube compressed. It looks even better streamed to my digital TV (via Airport Express) at home.