Funny you should ask....I just dove it last night for the first time. Here's my report I just posted on WIscuba.com:'
Finally got out to this lake for the first time. I couldn't find any info on the web, nor did anyone speak up to the posts I've made here or on scubaboard. The good news is that Bob from Fontana Outdoor Sports was very helpful. He gave me a couple pointers of where to go. He said that vis is up to 50' below the thermocline...and at the dock, the water was crystal clear down maybe 8-10', so I had high hopes of great vis.
The lake has a TON of rules, so if anyone goes out there, be sure to follow them. The first rule is that every diver must be registered with the water safety patrol. It's a one-time registration, good for life, and free. Other rules are: must dive from a boat, no shore diving, boat must have a flag, tow flag with diver not required, must surface within 50' from boat, must have "spotter" in boat, no solo diving, no diving in 3 areas of the lake for most of the year. Also, the police boat has a radar gun as there is a speed limit on the lake. Something like 35MPH during the day, and 15 at night. They had a boat "pulled over" on our way back at night, as he thought it was 25MPH, so they busted him. The lake is 9 miles long, so 15 MPH can take a while to get anywhere!
There are two large shipwrecks in the lake, along with some smaller craft. The 115' Lucius Newberry went down in 65 feet of water in 1891. It burned to the water line so there isn't much left. The 93' hull of an earlier Lady of the Lake excursion boat (there's a newer one running now) rests in only 35 feet of water. It went down in 1893. We decided to go to the deeper one, at 65', hoping to be well below the theromocline and into some good vis. BTW, this is a very deep lake, with shorlines dropping off to close to 100' VERY close to shore. Some of the bottom contours seem like a 45° incline. The map I have says 135' max, but the water safety patrol website says 162'. Anyway, we dropped down the anchor line to the wreck, only to find that vis wasn't much better on the bottom than on the stirred up top, maybe like 10' and very dark. I didn't bring my big light (didn't think it was going to be necessary), but I did have my very bright backup light, which I immediately put on. So, with the bad vis, I cut the dive short and decided to move to a different spot that was recommended, a point with fish cribs and fast drop off, called Black Point.
Went to this point and found the fish crib quickly. Everyone back in the water as the sun is setting (another Geneva lake rule...no diving after sunset). TONS of fish on a 10' tall crib in 19' of water. The bottom drops off to about 90' here quickly, but we stayed above 30'. Bluegill, crappie, smallmouth bass and rock bass. Slightly deeper and below the 25' thermocline was a ton of fairly large crayfish. One diver in the group got tangled up in some fishing line...not monofilament, but the superbraid stuff. The line ended up cutting his fin, being so strong and saw-like. On the end of the line was a Mepps spinner and a recently deceased crayfish. Vis here wasn't much better, maybe 15', and the bottom was more sandy.
We had launched in Williams Bay (nice launch, $7.50), but a long haul to the shipwrecks. The lake is 9 miles long and about 1 mile wide. The water in Williams Bay seemed so clear compared to the rest of the lake. Maybe it's because it was on the North side of the lake with a North wind blowing, so it wasn't stirred up much.
Definitely would like to dive there again, but would like better vis. (Getting spoiled with this Lake Michigan stuff.)
Chad
