I went diving here and enjoyed it, especially the Thermoclines. Water went from 78% to 95%. As you dive, you can see where the cold and hot water meet - it looks like a underwater bridge. Really cool.
The visibility is only 20 feet so stay close to your dive master. Also use less weight that you would when diving in the Sea.
Be advised that the hike to the lake is strenous. You must put on your scuba gear (except fins) then hike up and down some stairs. Be sure to take your time and hold on to the railings. I didn't have any problems but it can be a little slippery at times.