galveston state water

Went out to check a couple of numbers a coworker gave for some state snaper's. First spot couldn't find anything, he did say they were old numbers. Second one I found but couldn't get anything to bite but did see fish suspended between 20 and 30 feet. So I tried some ribbon fish floated with and with out a Float but no bite. Tried trolling around the area with ever king fish killer I had with still No bite. The spots where about 8.5 and 8.75 miles out and the water was pretty dirty. I guess that's why the call it fishing