First off what kind of fish is that and are those teeth?!?!
second the s3 has fully manual mode along with aperture priority and shutter priority and a iso speed settable up to 800, if you play around with it and read a coupl eof the stickies at the top of the forum I would think you should be able to get shots without the flash, But I have never used the camera so I can't say for a hundred percent.