I was there today and it is frozen solid!:head
I saw it freeze over with skim ice a few times last year when they were working on the plant, but this ice is so thick you could drive a 4-wheeler on it.
It was open, as well as half the lake, when I last dove there a couple weeks ago, but now the only openwater around here is the Yahara river where it connects Mendota to Monona. This is a nice paddle in winter, if you have a kayaking drysuit, but it's kind of shallow to dive. The water is clear and you can see the entire bottom from the banks and bridges.
Lake Michigan was open as of earlier today. My father-in-Law got out to do a few hours of side-scanning Thursday and said the lake was flat calm and clear, but we had some east winds during that storm yesterday.
IF your looking to dive there I would suggest South Shore yacht club- it's the easiest access to water and you can dive under the slips to look for lost tools, wallets, and dead cats- yes, I have found all of those things there in the past.
Another option is McKinley Marina, but south Shore has a much easier access. Diving the outside of the Marina, along Government Pier, is also a nice dive as there are many access ladders built into the side of the pier. I have climbed them in full scuba, during the winter, in the past and with freediving gear it would be a cinch. IF the wind and waves are right I've even done dives out there where we swim out till we get cold and then climb up onto a passing ice flow. Once on the iceberg we just ride it back to shore- and step onto the rocks where we end up next to our cars in the parking lot. It doesn't get much easier than that.:friday
If you want to throw a tank on, Toller, my father-in-law has a charter on New Year's day and another one next Saturday. These are scuba only as drysuits are required in the winter, as well as doubles, a pony bottle, or H-valve set-up. It's not that the water is too cold for a wetsuit, just that your miles out on the lake and the Coast Guard is of little help that time of year so drysuits are required above and below the water for safety's sake. In 24 years of winter charts there's never been a problem, but you still need to be prepared.
All of the above sounds like too much of a hassle for me this year so I might just sleep in a go for a long run in the snow.
Jon