The visibility in the quarries is BAD! And usually pretty COLD!
The vis at Haigh was up to 30 feet in June and July, it starts off good there in the spring, but by August or so the algea bloom and the vis is bad then. By July the surface temp is 70 degrees or so, and its in the 50's, almost 60 at deep hole, very nice.
Pearl Lake usually has bad vis early then gets better later in the season. Its probably about 20 feet now, but it will close after this weekend. Pearl gets into the 70's for surface in July & Aug and can be 50-60 degrees at depth.
One thing I always remember is the day I was certified was June 10th and the water temp at 50 feet (Haigh Quarry) was 45 degrees!
Yes, it can be cold!
I have never dove Lake Michigan, but I've heard the vis can get pretty good,
Or 40 feet. The vis can be great. In fact it has never been a problem on any of my 5 charters this year. One each month June-Oct.
And the temps get can't O.K. too, from what I've been told.
In July and August it is really comfortable. Seems to be warmer out of Chicago, and cooler as you go further north. It was COLD when I went out of Milwaukee on the 8th. 45 at the surface.
We'll have to get you into some of the cold water!
Yes, try it! If you dress appropriately, you can be very comfortable. It is really a rush diving Lake Michigan with the Chicago skyline on the horizon. Some of even think its magical.