Duck itch is alive and well in this part of the lake (Alton/Gilford line.) I have at least 30 of them right now and my husband has almost as many. Ditto with several neighbors.
Lathering up with sunscreen before swimming really does help, but be sure to lather up everywhere, even under your bathing suit. Also, don't dry off in a wet bathing suit, but rather change right away. "After Bite" ammonia pen works pretty well once you're itching like crazy.