My friend and I did something similar back in high school. We started when we would go out in his canoe, and we couldn't believe the amount of garbage floating in the back of coves. We would take a roll of black garbage bags and fill enough to load the canoe in only about 20-30 minutes. After that we started using my Norris Craft so we could haul more. Sam Venable mentioned us in one of his articles for the Knoxville News Sentinel. Some of the stuff we found was kind of scary. Syringes, pill bottles, etc. We found syringes almost every time we went.
I would disagree with the part about looking good to enforcement if checked, however. I got stopped by a female TWRA officer on Melton Hill one time while picking up garbage. She gave me a really hard time and kept me for about 45 minutes, asking me all kinds of questions and treating me really suspiciously. Checked my licenses, searched my boat, kept asking me what I was really up to, etc, etc. Finally told me not to be picking up garbage any more and told me it wasn't my job. That was the last time we ever picked up trash at the lake.