Hi,
I don't have expirience with the A70 but with other Canon Compact Cameras.
Here my quick tips:
- Use the Internal Flash allways beside wideangle (panoramic) shots.
- Shoot in the best Resolution and Quality your camera can.
- Get Close... if you think you are close enough get closer.
- Use the Macromode (Flower Symbol) when you try to photograph anything small or the pictures won't get sharp.
- Learn to tell how your subject (Fish) will move next and try to shoot early, since it will take some fractures of a second between pressing the shutter and the pic is actually made (shutter Lag). If you do this you can avoid a lot of "Fish Butt" Shots
- Get a good Photo Editing Program - Photoshop is best but you can also use Photoshop Elements, gimp or another lowcost program. You will probably want to do Level Corrections (very important when not using RAW files and Strobe) Backscatter removal (very important because of internal flash) and sharpening.
-Have Fun
Greetings from Germany
Simon