I had never been in Lake Michigan's waters in 5 years of Chicago living. I avoided the water because I had a valid fear that my skin might melt off my body if it touched the lake's waters. Running alongside the lakefront for years, I was consistently amazed at all the fuel, trash, sludge, and unknown crud that floated up.
For some reason people still waded off shore into the water. I figured it was too many afternoon beers at Castaways. I spent monday evening on Lake Michigan jet skiing. The weather was perfect and the lake was calm. Since it was monday, there were almost no boats on the water. We were able to let it rip to 60 mph for long stretches at a time.
After we'd cruised around for an hour or so, I got hot. I realized I was surrounded by water (duh) but would have to let go of one of my random oddities of never touching foot in the lake. We were far enough out that there was none of the usual slime skin on the water, or random trash floating by. I quickly jumped off the back of the jet ski without thinking.
It felt like a normal lake! I was relieved. I kept picturing a scene in RoboCop. The RoboCop falls into a vat of sulphuric acid, which would only happen in an 80s action movie. When he climbs out, his skin is melting off his body. I felt that getting into the cesspool known as Lake Michigan's shore would do that to me. I now realize that getting offshore far enough mitigates that risk. You still won't catch me wading in along North Ave Beach though.