I don't know if any of you all kayak or canoe, but we do almost every weekend until it snows. I have wrestled or participated in grappling type sports all of my life and never got ringworm. I have gotten it for the second time in the last month while kayaking. I guess dirty water is the same as a dirty mat or wrestling partner. It is pretty easy to get rid of. I just rub ointment on it for a few days and it goes away. But, it is contagious if you touch someone or apparently get back in the water with it.
It doesn't hurt, just makes you look like a jackass who doesn't wash. I posting this for those who do kayak or canoe. Check yourself when you get out of the water, just like checking for ticks after a hike. I'd hate for someone to pass it on to a spouse by.....well, you know....without knowing you even had it.
Looks like a red "tree ring". I've had it on my ankle and just today got it on my knee.