Bummer on the viz. I usually camp at Penninsula in mid-Sept, but didn't this year due to our first child being born a couple months ago. But I've already made reservations for next year!
I'm a newbie (warm water trained down in Trinidad & Tobago, got OW and AOW), but am looking forward to diving Door County next year. My buddy snorkeled somewhere off of the Penninsula State Park beach the last 2 years running on the same weekend and saw some wreck from the surface. He was amazed at the viz. Something like 30' he was saying.