Snapping turtles like to be able to lie on the bottom, and still reach the surface with their nostrils to take a breath. Keep the water level according to your turtles size. They will venture into deeper waters if you can provide a sloping element in the enclosure. Now, as far as basking...My snappers basked from hatchling until about a year old. But, i have seen wild adult snappers basking on muddy river banks in my 10+ years of studying and collecting wild common snappers.My 7 year old common does not bask, but thats just one turtle. Provide your turtle with a basking spot, and see what happens...good luck.