I recently bought a cheap kayak for exercise purposes. It gives me a change from bicycling on the Katy Trail or the little gym in our basement. I’ve been taking it out to Creve Coeur Lake Park a couple times a week. 
Creve Coeur Lake Park is 2200 acre park with a 320 acre lake about 10 or 15 minutes from the house. While Creve Coeur Lake is pretty and scenic it is not very clean. It is not very deep, 10 feet at the most. Also during times of flood on the Missouri River, this area all goes under water. And let’s face it, people are not always that clean, and a lot trash from the park ends up in the lake.
On Saturdays if the weather is even half way decent the park is very crowded. At the park in a small business that rents kayaks, canoes, and paddle boards. They also rent bicycles and those 4 wheel pedal powered machines that look like old time carriages (quadricycles). Saturdays can be Grand Central Station on the lake with kayaks, canoes and a multitude of paddle boards everywhere.
On Wednesdays, especially in the mornings, it is a different story. There are people on the trails, but the lake is nearly deserted. I had been out there close to an hour and was thinking about turning to go back across the lake in a few minutes. I noticed a splash in the water about 1/3 the distance from the far shore. At first I thought it was a really large fish. It is not uncommon to see fish breaking the water in their dining attempts. Then I realized that it was a bilateral, recurring splash. Since it was so far away, my next thought was that it was a very low profile kayak and I was seeing the splash of the paddles.
It did finally dawn on me that it was a swimmer. Now this is rather strange as it is posted in multiple spots around the lake that “Swimming Is Not Permitted”. As I cruised along the far shore, watching this individual, I realized that we were on a course of intersection if I did not alter my speed or direction. So out of orneriness or curiosity or both, I stayed the course.
We both arrived at a point on the far shore, more or less at the same time. There is no beach here, and the water is not accessible from the shore as it is so overgrown on the bank here. I would imagine the lake bottom to be very mucky. As he stood up taking off his swim goggles I could see it was a gentleman closer to 60 than he was to 50. Obviously he was very fit as he had just swam a good distance. A rough estimate using Google maps would be around a 1/3 of a mile and he had that to go back. Just for the record, this is a long way in the water. I am not quite sure why anyone would choose to do this, perhaps he was training for a triathlon.
As he finished taking off his goggles, I said, “You’re a braver man than I, swimming it this lake.” Next thing I heard was, “huuuhhhh?”, followed by the classic cartoon double take. He had no idea that he was not alone. I repeated my question to which he answered, “I certainly would not drink it.” I don’t drink the water when I swim, but I certainly have trouble keeping it out of my mouth.
I vaguely thought about saying something about no swimming allowed, but he was a grown man who I am sure could read. So I just kept that to myself.
I wished him a good swim back, and I took me and my kayak back across the lake.