The fist 15 yrs. of my life was spent diving the lakes of NE Pennsylvania. Some of them are so small you would never find them on a map. The lakes have many varieties of fish: bluegill, s.m. bass, perch, walleye, catfish, trout, etc.
Once you descend below the thermocline, the visibility would commonly reach between 20 - 40 ft (depending on the time of year and weather conditions).
Diving in Pa lakes means cold water diving. During the summer months the surface water temp. would commonly reach in the mid 70's but below the thermocline the temp. would drop into the mid 40's. This meant layering with neoprene. I commonly dove with 6.5mm farmer-john and jacket, hooded vest , three-fingered neoprene mittens and boots.
Besides from fish watching, one of our favorite past-times would be searching for antique bottles. We found all varieties from local bottling companies that have all since vanished: milk, beer, medicine, soda. I found a Coke bottle that was dated December 25, 1916. Apparently Coke dated their bottles back in the old days.