Visibility varies a lot at Innerkip, from 20 feet on a good day in late spring, to 1 foot on a bad day in the fall. The bottom is really silty. Best visibility is usually late May to early July. Go after at least 5 days of no rain and not much wind.
I suggest a 2 tank dive. There are about 20 sunken boats, cars, buses, and pieces of plane--although they are heavily rusted out. Plus lots of fish--bass, suckers, carp, etc. You could do one dive on the North side, and one on the South. Or use one dive to explore, and for the other, use the map and a compass to try to navigate around and hit all the objects. Do you have a map?
I prefer Innerkip over Gulliver's, because there is lots more to see an Innerkip (on an Ontario quarry scale of "lots more to see."). Visibility is better at Gulliver's.