Well, its lake diving. You need to be ready for it.
It is cold, even in the summer. All I can really say is to enjoy what is there.
To look at the lake off the bat, there isnt much there to be honest.
But if you really enjoy diving, anyone from DD will be able to show you a good time.
There are a couple walls you can check out over near the westside.
The best dive I could suggest is to do the OK Bridge at night. Its definatly a dive you need a guide on, easy to get lost under there if your not used to the area. But if you have a good guide, hit the bottom, turn your lights off and look up and listen. Its creepy but a very cool dive at the same time! Again, I must stress that you have a guide for that dive though, even if you have alot of night diving expierence!
I would take you if I still lived in the area.
Contact DD. Im sure they will be happy to tell you what dives are avaliable!