Useful resource for inland diving in North America

[Pezman]

Here's a site that I came across that can be useful for getting a grip on the visibility that can be expected in various North American lakes:

http://dipin.kent.edu/lake.asp

For example, I was able to find that Marsh Creek Lake, which is pretty close to my house, often has visibilty in excess of 4 meters (good enough for me!). Since Marsh Creek allows diving, has muskies and other big fish etc., I'm going to give it a try ASAP.

Maybe other folks know about similar sites?