The problem with tidepool filming is that your timing is almost never right. You need the tide to be out far enough to give you access to the deeper pools and you can't have had high surf or rains beforehand because of the sediment it stirs up. I figured a lake would have none of these problems, so off I went to Lake Murray to film.
The reeds seemed to have the most promise to find little fish or other creatures and the water looked clear. I had no problem clearly seeing the bottom. The camera wasn't so lucky. The focal length on my PlaySport is 3', so I chose a distance from the reeds of about 5' to make sure everything would be in focus. Instead, I just got a bunch of muddy water.
The video is only a minute and there's an HD version that will make the mud really pop on your screen. If you're into that sort of thing.