Sven,
The aga's are still around. We have a hard wired unit that we use once in a while. The mask uses more gas than a cressi full-face or a regular half mask. I think that the local dive rescue teams are using the OTS system. They have some aga's and some exo-26's that they use.
Are the new OMS 46's similar to the old aga tanks? I know that they can be manifolded and slung however you want.
Doug,
Lake Huron has some of the prettiest wrecks that I have seen. I was on the Newel Eddy not too long after she was found. It was great to start at the top of the mast(38') and spiral down to the crow's nest (90'), then continue down to the main deck at 150. I think that she bottomed out at about 167', or something close. She had so much stuff on her back then.
All of the lakes have cleared up quite a bit thanks to the zebra mussles. When I started diving lake Michigan we never had more than 5-8' of vis. If it got up to 15' people closed down their shops to dive.
Now, I have actually measured out 80' of visibility in the winter time. Summer will often bring about 40'-60' on a pretty regular basis. When you get to the deepr wrecks, past 160', the vis can get up to 30' but is usually down around 8-10'. The depths that I freedive to, 60-100', the vis is always a good 30-40'.
When I lived in Milwaukee we would do salvage jobs to supplment the charters and scuba classes that we ran.
Jon