Dale Hollow is wonderful. I started diving there in 1983. Back then the lake was full of
fresh water clams.
The clams are gone now, mainly due to pollution. However Dale Hollow is cleaner (as far as pollution) than Laurel Lake & Lake Cumberland and this makes it my choice of lakes to dive. It farthest for me to drive as we are in Lexington, but I'll take the cleanest lake any day of the week.
There are some descent dive sites near Pine Island. We used to camp on Pine Island then take the boat for an off shore dive near some of the old towns/neighborhoods that remained when the area was flooded.
Nothing is left of them except a tractor or two, foundations of the houses, and the occasional fence row that hasn't rotted or rusted away yet. There is still marine life in these areas and it's great for nesting fish like "Kentucky Piranha" and bass.
Someone had mentioned the diveshop on the lake, yes...it's the best to find out where to dive and they usually have maps of where to dive.
If you dive from a boat, there are some areas in Dale Hollow that have this plant that grows from the bottom to the surface (kelp like I guess). Be careful as entanglement can be an issue. The plants are easily spotted from the surface and I've only seen them back in coves.