I bought an EWA marine bag for my 7D with the intention of trying to photograph the pumpkinseed sunfish that nest on the flat rock of my little lake's shoreline.
By the time I was able to try it out there was just one pumkinseed left guarding its nest, hence the title.
The lake is tea-coloured with lots of vegetation and therefore lots of stuff floating around in it. The walkway to my small pipe dock restricts moving around the nests and any movement would stir up too much silt to photograph. I came up with the idea of staying on the dock and placing the bag on the bottom near the nest. Then, of course, there is still the sun and wave action to consider.
With just one lead weight in the bag it floated too far above the nest and I captured no video of the fish as he was below the lens. I bought 12 lbs of weights at a dive shop and attached them to the outside of the bag. Still not perfect but much better.
The next challenge is the lighting and I think I have a solution to that.
Not exactly the clear water and colorful fish of the Barrier Reef but here is my best attempt.
http://www.youtube.com/watch?v=ytWJENboMcA
Thanks for looking!