I too have had duck itch each summer for the past five years. I swim every weekend and have found that when I get it is when I have been nearest the shore where it is rocky. I have never gotten it when swimming out from the shore or off a boat. It is my understanding that the parasite clings to rocks. I am very susceptible to it although my husband has never had a problem with it and we swim in the same areas. Then again he doesn't get affected by poison ivy either.
